<div dir="ltr">On Sun, Dec 25, 2016 at 10:50 PM, Daniel Leping <span dir="ltr"><<a href="mailto:daniel@crossroadlabs.xyz" target="_blank">daniel@crossroadlabs.xyz</a>></span> wrote:<br><div class="gmail_extra"><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><div>Ok, an example from ORM. You have an entity factory with a virtual (read, overloadable in the subclasses) method populating the properties. DefaultConstructable is a great choice here. Otherwise you will have to force the users of your ORM to implement a certain protocol, which you most probably would like to avoid.</div></blockquote><div><br></div><div>Sorry--I'm not very familiar with using Swift for ORM purposes. Why do you want to avoid having your users conform to a certain protocol? Wouldn't the users of your ORM have to conform to `DefaultConstructible` then? I'm looking at Swift ORMs, and all require users to conform to a protocol or inherit from a base class, typically named `Model` or similar. From a quick Google search:</div><div><br></div><div><a href="https://vapor.github.io/documentation/fluent/model.html">https://vapor.github.io/documentation/fluent/model.html</a><br></div><div><a href="https://github.com/blitzagency/amigo-swift">https://github.com/blitzagency/amigo-swift</a></div><div> <br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><div>In general I think the best showcase is generic factories.</div><div><br><div class="gmail_quote"><div>On Mon, 26 Dec 2016 at 9:02 Xiaodi Wu <<a href="mailto:xiaodi.wu@gmail.com" target="_blank">xiaodi.wu@gmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><div class="gmail-m_-5467957317484069493gmail_msg">On Sun, Dec 25, 2016 at 10:18 PM, Daniel Leping <span class="gmail-m_-5467957317484069493gmail_msg"><<a href="mailto:daniel@crossroadlabs.xyz" class="gmail-m_-5467957317484069493gmail_msg" target="_blank">daniel@crossroadlabs.xyz</a>></span> wrote:<br class="gmail-m_-5467957317484069493gmail_msg"></div><div class="gmail-m_-5467957317484069493gmail_msg"><div class="gmail_extra gmail-m_-5467957317484069493gmail_msg"><div class="gmail_quote gmail-m_-5467957317484069493gmail_msg"><blockquote class="gmail_quote gmail-m_-5467957317484069493gmail_msg" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><div class="gmail-m_-5467957317484069493gmail_msg">Usually it's a generic function that needs to return a value from some other function or a default value (zero) in a case of some conditions. Optional value is an arguable solution in quite some scenarios. Afaik, sometimes it can be used for optional resolution.</div></blockquote><div class="gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493gmail_msg"></div></div></div></div><div class="gmail-m_-5467957317484069493gmail_msg"><div class="gmail_extra gmail-m_-5467957317484069493gmail_msg"><div class="gmail_quote gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493gmail_msg">Right, I'd agree that Optional is the idiomatic way to do it. Afaict, there's not much you can do with a default value that you couldn't with nil, unless you have some guarantee as to _what_ that default is; however, I'd expect that in every case that you can rely on a guarantee about a default value which would be more useful than nil, it's going to require more specific knowledge of your type than an all-encompassing `DefaultConstructible` can provide.</div></div></div></div><div class="gmail-m_-5467957317484069493gmail_msg"><div class="gmail_extra gmail-m_-5467957317484069493gmail_msg"><div class="gmail_quote gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493gmail_msg"></div><blockquote class="gmail_quote gmail-m_-5467957317484069493gmail_msg" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><div class="gmail-m_-5467957317484069493gmail_msg">Also, generic factories. Widely used in ORM solutions.</div></blockquote><div class="gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493gmail_msg"></div></div></div></div><div class="gmail-m_-5467957317484069493gmail_msg"><div class="gmail_extra gmail-m_-5467957317484069493gmail_msg"><div class="gmail_quote gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493gmail_msg">Can you elaborate on this? Why is Optional not a solution here?</div></div></div></div><div class="gmail-m_-5467957317484069493gmail_msg"><div class="gmail_extra gmail-m_-5467957317484069493gmail_msg"><div class="gmail_quote gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493gmail_msg"> </div><blockquote class="gmail_quote gmail-m_-5467957317484069493gmail_msg" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><div class="gmail-m_-5467957317484069493gmail_msg">As mentioned above, algorythmical stuff that requires Zero.</div></blockquote><div class="gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493gmail_msg"></div></div></div></div><div class="gmail-m_-5467957317484069493gmail_msg"><div class="gmail_extra gmail-m_-5467957317484069493gmail_msg"><div class="gmail_quote gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493gmail_msg">I'm still not convinced there exist credible use cases that need to be generic over both collections and floating point, for instance. In fact, in my experience, there are few math-heavy algorithms where one can ignore even the distinction between integers and binary floating point. By the time you get down to matrix math, you start to run into difficulties that require separate implementations for Float and Double.</div></div></div></div><div class="gmail-m_-5467957317484069493gmail_msg"><div class="gmail_extra gmail-m_-5467957317484069493gmail_msg"><div class="gmail_quote gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493gmail_msg"></div><blockquote class="gmail_quote gmail-m_-5467957317484069493gmail_msg" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><div class="gmail-m_-5467957317484069493m_4646774645923960753HOEnZb gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753h5 gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493gmail_msg"><div class="gmail_quote gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493gmail_msg">On Mon, 26 Dec 2016 at 8:38 Xiaodi Wu <<a href="mailto:xiaodi.wu@gmail.com" class="gmail-m_-5467957317484069493gmail_msg" target="_blank">xiaodi.wu@gmail.com</a>> wrote:<br class="gmail-m_-5467957317484069493gmail_msg"></div><blockquote class="gmail_quote gmail-m_-5467957317484069493gmail_msg" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">Can you give some examples of what you used this approach to do?</div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail_extra gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div><div class="gmail_extra gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail_quote gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">On Sun, Dec 25, 2016 at 9:49 PM, Daniel Leping <span class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><<a href="mailto:daniel@crossroadlabs.xyz" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg" target="_blank">daniel@crossroadlabs.xyz</a>></span> wrote:<br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><blockquote class="gmail_quote gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">+1 to this approach. I remember I had to create it on my own for my projects. Would be nice to have it out of the box.</div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348HOEnZb gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348h5 gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail_quote gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">On Mon, 26 Dec 2016 at 8:11 Adam Nemecek via swift-evolution <<a href="mailto:swift-evolution@swift.org" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg" target="_blank">swift-evolution@swift.org</a>> wrote:<br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div><blockquote class="gmail_quote gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">> <span style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">Yes, those particular types have initializers that take no arguments. That does not address my question. You merely restated your initial observation that many types in Swift have implemented `init()`.</span></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><span style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></span></div></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><span style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">Right, it's an empirical argument.</span></div></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div>> <span style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">I didn't think the value returned by `init()` was regarded as any sort of zero--or even any sort of "default." In fact, some types in Foundation have a static property called `default` distinct from `init()`.</span><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><span style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></span></div></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><span style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">Let's not talk about those then. This would not apply to every single type in existence, as I've stated previously.</span></div></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><span style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></span></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><span style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">> </span><span style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">It gives you something different every time. How can this be squared with your stated motivation regarding concepts of zero and concepts of equality?</span></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><span style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></span></div></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><span style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">Due to the fact that it's a resource, not a value. As I've stated above, not all of this applies to types that are more resource-like.</span></div></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">> <span style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">Or, it's what you get because that's the most trivial possible string. Quite simply, I do not think the designer of most types that implement `init()` have paused to wonder whether the value that you get is the identity element associated with the most useful and prominent operation that can be performed on that type. I certainly never have.</span><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><span style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></span></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><span style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">This is an appeal to tradition. </span></div></div></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><span style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></span></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><span style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">> </span><span style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">The statement I wrote was in JavaScript, so I'm not sure what you mean by returning an optional. `[]</span><span style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">.reduce((a, b) => a + b)` results in an error in JavaScript. In Swift, such a function may also be implemented with a precondition that the array is not empty and would not return an optional.</span></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><span style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></span></div></div></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><span style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">I was talking about their </span><span style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">analogous </span><span style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">swift implementations.</span></div></div></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">> <span style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">Can you give an example of an algorithm dealing with tensors where you would use a `DefaultConstructible` generic over all types that have `init()`, as opposed to working with the existing `Integer`, `FloatingPoint`, and other numerical protocols?</span></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><span style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></span></div></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><span style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">If it's implemented as either nested collections or numbers. </span></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><span style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></span></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div></div><div class="gmail_extra gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail_quote gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">On Sun, Dec 25, 2016 at 6:00 PM, Xiaodi Wu <span class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><<a href="mailto:xiaodi.wu@gmail.com" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg" target="_blank">xiaodi.wu@gmail.com</a>></span> wrote:<br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><blockquote class="gmail_quote gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><span class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">On Sun, Dec 25, 2016 at 7:30 PM, Adam Nemecek <span class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><<a href="mailto:adamnemecek@gmail.com" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg" target="_blank">adamnemecek@gmail.com</a>></span> wrote:<br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></span><div class="gmail_extra gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail_quote gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><span class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><blockquote class="gmail_quote gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><span class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail- gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><span style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">> Is it well settled, either in Swift or in C++/Rust/etc., that the value returned by a default initializer/constructor is regarded as an identity element or zero? </span><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><span style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></span></div></span><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><span style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">Int() == 0, String() == "" so to some extent by convention, a lot of types have a default value as is.</span></div></div></blockquote><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div></span><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">Yes, those particular types have initializers that take no arguments. That does not address my question. You merely restated your initial observation that many types in Swift have implemented `init()`.</div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">I didn't think the value returned by `init()` was regarded as any sort of zero--or even any sort of "default." In fact, some types in Foundation have a static property called `default` distinct from `init()`. In Rust, the Default trait requires a function called `default()`, which is documented as being useful when you want "some kind of default value, and don't particularly care what it is."</div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">I was asking whether there's some understanding, of which I've been unaware, that the result of `init()` (or the equivalent in other languages) is expected to be some sort of zero or an identity element. I'm not aware of any evidence to that effect. Are you?</div><span class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div><blockquote class="gmail_quote gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><span class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail- gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><span style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">> Is the thread that I get by writing `let t = Thread()` some kind of zero in any reasonable sense of the word?</span><span style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></span></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><span style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></span></div></span><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><span style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">DefaultConstructibility makes less sense for types that represent some sort of resource but make sense for things that are values. But even in this case, Thread() gives you a default value for example if you are working with a resizable collection of threads.</span></div></div></blockquote><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div></span><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">It gives you something different every time. How can this be squared with your stated motivation regarding concepts of zero and concepts of equality?</div><span class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div><blockquote class="gmail_quote gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><span style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">A better question is why does thread currently implement a default constructor? </span></div></div></blockquote><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div></span><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">It's an initializer that takes no arguments, because none are needed for a new thread. How else would you write it?</div><span class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div><blockquote class="gmail_quote gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><span class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail- gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">> Do you mean to argue that for an integer the additive identity should be considered "more prominent and useful" than the multiplicative identity? I'm not aware of any mathematical justification for such a conclusion.</div></div><div style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div></span><div style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">I do. The justification is that if I call the default constructor of Int currently, I get the value of 0.</div></div></blockquote><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div></span><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">This is backwards. Why do you believe that the value you obtain from `init()` is intended to be an identity element at all, let alone the most important one? (It's also circular reasoning. Since `init()` only ever gives you one value at a time, by your reasoning it demonstrates that every type must have one "more prominent and useful" identity, which is begging the question.)</div><span class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div><blockquote class="gmail_quote gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">Which means that the binary operation must be addition.</div></div></blockquote><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div></span><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">Based on the value of `Int.init()`, you conclude that addition of integers is a "more prominent and useful" operation than multiplication? Again, this is backwards. Rather, we know that each numerical type belongs to multiple ring algebras; there is no basis for reckoning any as "more useful." Since `init()` can only ever give us one value at a time, we know that `init()` cannot give a value that is a meaningful default with respect to any particular operation.</div><span class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div><blockquote class="gmail_quote gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">If I call String() I get "" which is the identity of the + String operation.</div></div></blockquote><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div></span><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">Or, it's what you get because that's the most trivial possible string. Quite simply, I do not think the designer of most types that implement `init()` have paused to wonder whether the value that you get is the identity element associated with the most useful and prominent operation that can be performed on that type. I certainly never have.</div><span class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div><blockquote class="gmail_quote gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><span class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail- gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">> <span style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">Going to your original example, I should add: other languages provide a version of `reduce` that doesn't require an initial result (for instance, JavaScript). In JavaScript, `[1, 2, 3].reduce((a, b) => a + b)` uses the element at array index 0 as the initial result, and the accumulator function is invoked starting with the element at array index 1. This is precisely equivalent to having `reduce` use the additive identity as the default initial result when + is the accumulator function and the multiplicative identity when * is the accumulator function (with the accumulator function being invoked starting with the element at array index 0). It does not require a DefaultConstructible protocol. What more ergonomic solution could be implemented using a monoidic wrapper type?</span></div><div style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><span style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></span></div></span><div style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">These two will have different signatures. The reduce you describe returns an optional,</div></div></blockquote><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div></span><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">The statement I wrote was in JavaScript, so I'm not sure what you mean by returning an optional. `[]<span style="font-size:12.800000190734863px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">.reduce((a, b) => a + b)` results in an error in JavaScript. In Swift, such a function may also be implemented with a precondition that the array is not empty and would not return an optional.</span></div><span class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div><blockquote class="gmail_quote gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">the other one would returns the default value.</div></div></blockquote><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div></span><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">In what scenario would you prefer to propagate a default after reducing a potential empty collection _without supplying an explicit default_ for that operation? This would certainly violate the Swift convention of not defaulting to zero and, I suspect, most users of Swift would not regard that as ergonomic at all.</div><span class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"> </div><blockquote class="gmail_quote gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">Fundamentally the default constructibles are useful in numerical computations e..g. dealing with tensors.</div></div></blockquote><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div></span><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">Can you give an example of an algorithm dealing with tensors where you would use a `DefaultConstructible` generic over all types that have `init()`, as opposed to working with the existing `Integer`, `FloatingPoint`, and other numerical protocols? (I should also add, FWIW, I have never seen a generic algorithm written for integers or FP types that has preferred the use of `T()` over `0`.)</div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809h5 gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div><blockquote class="gmail_quote gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-HOEnZb gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-h5 gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail_extra gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail_quote gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">On Sun, Dec 25, 2016 at 3:30 PM, Xiaodi Wu <span class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><<a href="mailto:xiaodi.wu@gmail.com" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg" target="_blank">xiaodi.wu@gmail.com</a>></span> wrote:<br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><blockquote class="gmail_quote gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><span class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">On Sun, Dec 25, 2016 at 5:27 PM, Adam Nemecek <span class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><<a href="mailto:adamnemecek@gmail.com" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg" target="_blank">adamnemecek@gmail.com</a>></span> wrote:<br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></span><div class="gmail_extra gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail_quote gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><span class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><blockquote class="gmail_quote gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><span class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail- gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">> <span style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">*Which* APIs become more ergonomic?</span></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><span style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></span></div></span><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">I'll get back to this question in a second if I may. This would be a longer discussion and I first want to make sure that before we get into the details that there is a possibility of this being introduced (I'm asking if violating the no zero defaults is more important than slightly more ergonomic APIs). But to give a broad answer I think that the concept of a zero is closely related to the concept of equality (and all the things that build up on equality such as comparability and negation). </div><span class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail- gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">> <span style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">1) How does this square with Swift’s general philosophy to not default initialize values to “zero”?</span></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><span style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></span></div></span><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><span style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">I actually wasn't aware of this philosophy. Despite this philosophy, look at how many types actually currently implement a default constructor.</span></div></div></blockquote><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div></span><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">(Not a rhetorical question:) Is it well settled, either in Swift or in C++/Rust/etc., that the value returned by a default initializer/constructor is regarded as an identity element or zero? Is the thread that I get by writing `let t = Thread()` some kind of zero in any reasonable sense of the word?</div><span class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"> </div><blockquote class="gmail_quote gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><span style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">Also can I ask what's the motivation behind this philosophy? </span></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><span style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">I think that in Swift, default constructibility makes complete sense for (most?) structs, maybe less so for classes. </span></div><span class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail- gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div>> <span style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">2) To your original example, it isn’t immediately clear to me that reduce should choose a default identity. Some types (e.g. integers and FP) belong to multiple different ring algebras, and therefore have different identity values that correspond to the relevant binary operations.</span><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><span style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></span></div></span><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><span style="font-size:12.8px" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">This is a good point that I've considered as well but felt that for the most part, there is one particular identity and associated operation that is more prominent and useful than others. Furthermore, modeling different algebras isn't mutually exclusive with writing generic algorithms that rely on this protocol, you can always introduce some monoidic wrapper type that defines the more appropriate default value and operation.</span></div></div></blockquote><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div></span><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">Do you mean to argue that for an integer the additive identity should be considered "more prominent and useful" than the multiplicative identity? I'm not aware of any mathematical justification for such a conclusion.</div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">Going to your original example, I should add: other languages provide a version of `reduce` that doesn't require an initial result (for instance, JavaScript). In JavaScript, `[1, 2, 3].reduce((a, b) => a + b)` uses the element at array index 0 as the initial result, and the accumulator function is invoked starting with the element at array index 1. This is precisely equivalent to having `reduce` use the additive identity as the default initial result when + is the accumulator function and the multiplicative identity when * is the accumulator function (with the accumulator function being invoked starting with the element at array index 0). It does not require a DefaultConstructible protocol. What more ergonomic solution could be implemented using a monoidic wrapper type?</div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376h5 gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div></div><blockquote class="gmail_quote gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-HOEnZb gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-h5 gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail_extra gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail_quote gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">On Sun, Dec 25, 2016 at 1:24 PM, Chris Lattner <span class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><<a href="mailto:clattner@apple.com" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg" target="_blank">clattner@apple.com</a>></span> wrote:<br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><blockquote class="gmail_quote gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><div style="word-wrap:break-word" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><span class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">On Dec 25, 2016, at 12:54 PM, Adam Nemecek via swift-evolution <<a href="mailto:swift-evolution@swift.org" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg" target="_blank">swift-evolution@swift.org</a>> wrote:</span><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><span class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><blockquote type="cite" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">Does enabling a lot of small improvements that make APIs more ergonomic count as practical?</div></div></blockquote><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div></span><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">Yes, that would count as practical, but Xiaodi’s question is just as important. *Which* APIs become more ergonomic?</div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">Here are a couple of more questions:</div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">1) How does this square with Swift’s general philosophy to not default initialize values to “zero”?</div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">2) To your original example, it isn’t immediately clear to me that reduce should choose a default identity. Some types (e.g. integers and FP) belong to multiple different ring algebras, and therefore have different identity values that correspond to the relevant binary operations.</div><span class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596HOEnZb gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><font color="#888888" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">-Chris</div></font></span><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596h5 gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><blockquote type="cite" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail_extra gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail_quote gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">On Sun, Dec 25, 2016 at 12:19 PM, Xiaodi Wu <span class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><<a href="mailto:xiaodi.wu@gmail.com" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg" target="_blank">xiaodi.wu@gmail.com</a>></span> wrote:<br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><blockquote class="gmail_quote gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><span class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">On Sun, Dec 25, 2016 at 3:07 PM, Adam Nemecek <span class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><<a href="mailto:adamnemecek@gmail.com" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg" target="_blank">adamnemecek@gmail.com</a>></span> wrote:<br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></span><div class="gmail_extra gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail_quote gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><span class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><blockquote class="gmail_quote gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">There's a book that provides quite a bit of info on this <div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><a href="https://smile.amazon.com/Elements-Programming-Alexander-Stepanov/dp/032163537X?sa-no-redirect=1" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg" target="_blank">https://smile.amazon.com/<wbr>Elements-Programming-<wbr>Alexander-Stepanov/dp/<wbr>032163537X?sa-no-redirect=1</a><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">They say that DefaultConstructible is one of the essential protocols on which most algorithms rely in one way or another. One of the authors is the designer of the C++ STL and basically the father of modern generics.</div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">This protocol is important for any algebraic structure that deals with the concept of appending or addition (as "zero" is one of the requirements of monoid). There isn't a good short answer to your question. It's a building block of algorithms. Think about why a RangeReplaceableCollection can provide you with a default constructor but a Collection can't. </div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><span style="color:rgb(80,0,80)" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></span></div></div></blockquote><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div></span><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">It's well and fine that most algorithms rely on the concept in one way or another. Yet the Swift standard library already implements many generic algorithms but has no DefaultConstructible, presumably because there are other protocols that guarantee `init()` and the algorithms being implemented don't need to be (practically speaking) generic over all DefaultConstructible types. My question is: what practical use cases are there for an explicit DefaultConstructible that are impractical today?</div><span class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div><blockquote class="gmail_quote gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><span style="color:rgb(80,0,80)" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">On Sun, Dec 25, 2016 at 11:37 AM, Xiaodi Wu </span><span style="color:rgb(80,0,80)" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><<a href="mailto:xiaodi.wu@gmail.com" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg" target="_blank">xiaodi.wu@gmail.com</a>></span><span style="color:rgb(80,0,80)" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"> wrote:</span><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596m_-267952324834337685m_8912025549324475289HOEnZb gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596m_-267952324834337685m_8912025549324475289h5 gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail_extra gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail_quote gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><blockquote class="gmail_quote gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex">Can you give some other examples of generic algorithms that would make use of this DefaultConstructible? I'm having trouble coming up with any other than reduce.<br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail_quote gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596m_-267952324834337685m_8912025549324475289m_699475458640075951h5 gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">On Sun, Dec 25, 2016 at 14:23 Adam Nemecek via swift-evolution <<a href="mailto:swift-evolution@swift.org" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg" target="_blank">swift-evolution@swift.org</a>> wrote:<br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div></div></div><blockquote class="gmail_quote gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596m_-267952324834337685m_8912025549324475289m_699475458640075951h5 gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596m_-267952324834337685m_8912025549324475289m_699475458640075951m_-6015751673947924360gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">This protocol is present in C++ <a href="http://en.cppreference.com/w/cpp/concept/DefaultConstructible" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596m_-267952324834337685m_8912025549324475289m_699475458640075951m_-6015751673947924360gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg" target="_blank">http://en.cppreference.<wbr>com/w/cpp/concept/<wbr>DefaultConstructible</a> as well as in Rust <a href="https://doc.rust-lang.org/std/default/" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596m_-267952324834337685m_8912025549324475289m_699475458640075951m_-6015751673947924360gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg" target="_blank">https://doc.rust-lang.org/std/<wbr>default/</a><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596m_-267952324834337685m_8912025549324475289m_699475458640075951m_-6015751673947924360gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596m_-267952324834337685m_8912025549324475289m_699475458640075951m_-6015751673947924360gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596m_-267952324834337685m_8912025549324475289m_699475458640075951m_-6015751673947924360gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">It's the identity element/unit of a monoid or a zero.<br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596m_-267952324834337685m_8912025549324475289m_699475458640075951m_-6015751673947924360gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596m_-267952324834337685m_8912025549324475289m_699475458640075951m_-6015751673947924360gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596m_-267952324834337685m_8912025549324475289m_699475458640075951m_-6015751673947924360gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596m_-267952324834337685m_8912025549324475289m_699475458640075951m_-6015751673947924360gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596m_-267952324834337685m_8912025549324475289m_699475458640075951m_-6015751673947924360gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">The Swift implementation is very simple (I'm open to different names)<br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596m_-267952324834337685m_8912025549324475289m_699475458640075951m_-6015751673947924360gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596m_-267952324834337685m_8912025549324475289m_699475458640075951m_-6015751673947924360gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596m_-267952324834337685m_8912025549324475289m_699475458640075951m_-6015751673947924360gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596m_-267952324834337685m_8912025549324475289m_699475458640075951m_-6015751673947924360gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">protocol DefaultConstructible {</div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596m_-267952324834337685m_8912025549324475289m_699475458640075951m_-6015751673947924360gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"> init() </div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596m_-267952324834337685m_8912025549324475289m_699475458640075951m_-6015751673947924360gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">}</div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596m_-267952324834337685m_8912025549324475289m_699475458640075951m_-6015751673947924360gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596m_-267952324834337685m_8912025549324475289m_699475458640075951m_-6015751673947924360gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596m_-267952324834337685m_8912025549324475289m_699475458640075951m_-6015751673947924360gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">A lot of the standard types could then be made to conform to this protocol. These include all the numeric types, collection types (array, set, dict), string, basically at least every type that currently has a constructor without any arguments.</div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596m_-267952324834337685m_8912025549324475289m_699475458640075951m_-6015751673947924360gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596m_-267952324834337685m_8912025549324475289m_699475458640075951m_-6015751673947924360gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596m_-267952324834337685m_8912025549324475289m_699475458640075951m_-6015751673947924360gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">The RangeReplaceableCollection protocol would inherit from this protocol as well. <br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596m_-267952324834337685m_8912025549324475289m_699475458640075951m_-6015751673947924360gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596m_-267952324834337685m_8912025549324475289m_699475458640075951m_-6015751673947924360gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596m_-267952324834337685m_8912025549324475289m_699475458640075951m_-6015751673947924360gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596m_-267952324834337685m_8912025549324475289m_699475458640075951m_-6015751673947924360gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">This protocol would simplify a lot of generic algorithms where you need the concept of a zero (which shows up a lot)</div></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596m_-267952324834337685m_8912025549324475289m_699475458640075951m_-6015751673947924360gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596m_-267952324834337685m_8912025549324475289m_699475458640075951m_-6015751673947924360gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596m_-267952324834337685m_8912025549324475289m_699475458640075951m_-6015751673947924360gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">Once introduced, Sequence could define an alternative implementation of reduce where the initial result doesn't need to be provided as it can be default constructed.</div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596m_-267952324834337685m_8912025549324475289m_699475458640075951m_-6015751673947924360gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596m_-267952324834337685m_8912025549324475289m_699475458640075951m_-6015751673947924360gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596m_-267952324834337685m_8912025549324475289m_699475458640075951m_-6015751673947924360gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596m_-267952324834337685m_8912025549324475289m_699475458640075951m_-6015751673947924360gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596m_-267952324834337685m_8912025549324475289m_699475458640075951m_-6015751673947924360gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596m_-267952324834337685m_8912025549324475289m_699475458640075951m_-6015751673947924360gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596m_-267952324834337685m_8912025549324475289m_699475458640075951m_-6015751673947924360gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596m_-267952324834337685m_8912025549324475289m_699475458640075951m_-6015751673947924360gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div><div class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596m_-267952324834337685m_8912025549324475289m_699475458640075951m_-6015751673947924360gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596m_-267952324834337685m_8912025549324475289m_699475458640075951m_-6015751673947924360gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div></div></div></div></div><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">______________________________<wbr>_________________<br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596m_-267952324834337685m_8912025549324475289m_699475458640075951m_-6015751673947924360gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg">swift-evolution mailing list<br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596m_-267952324834337685m_8912025549324475289m_699475458640075951m_-6015751673947924360gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><a href="mailto:swift-evolution@swift.org" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596m_-267952324834337685m_8912025549324475289m_699475458640075951m_-6015751673947924360gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg" target="_blank">swift-evolution@swift.org</a><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596m_-267952324834337685m_8912025549324475289m_699475458640075951m_-6015751673947924360gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><a href="https://lists.swift.org/mailman/listinfo/swift-evolution" rel="noreferrer" class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596m_-267952324834337685m_8912025549324475289m_699475458640075951m_-6015751673947924360gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg" target="_blank">https://lists.swift.org/<wbr>mailman/listinfo/swift-<wbr>evolution</a><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359m_3012462067322088809m_1176161565890972384gmail-m_2687622816934730376m_-5821329404718624302gmail-m_3993794689939404596m_-267952324834337685m_8912025549324475289m_699475458640075951m_-6015751673947924360gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></blockquote></div><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></blockquote></div><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688m_-767592733113527348m_4453439987323397359gmail_msg gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"></div><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg gmail-m_-5467957317484069493gmail_msg"><br class="gmail-m_-5467957317484069493m_4646774645923960753m_-687985868842093688gmail_msg 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