[swift-users] Any way to declare a method that suppresses the string interpolation warning?

[Rick Mann]

> On Apr 30, 2017, at 11:30 , Saagar Jha <saagar at saagarjha.com> wrote:
> 
> Apologize for the late response, this message got buried in my inbox.
> 
> Saagar Jha
> 
>> On Apr 23, 2017, at 23:23, Rick Mann <rmann at latencyzero.com> wrote:
>> 
>>> 
>>> On Apr 22, 2017, at 12:23 , Saagar Jha <saagar at saagarjha.com> wrote:
>>> 
>>> 
>>> Saagar Jha
>>> 
>>>> On Apr 21, 2017, at 04:35, Rick Mann via swift-users <swift-users at swift.org> wrote:
>>>> 
>>>> I have a debugLog() method that looks like this:
>>>> 
>>>> func
>>>> debugLog<T>(_ inMsg: T, _ inFile : String = #file, _ inLine : Int = #line)
>>> 
>>> Well, for starters, I don’t see why you need to make this function generic. Why not make inMsg an `Any?`?
>> 
>> So I can write debugLog(<something other than string>)
> 
> Have you tried using `Any?`? You can pass in other stuff…

That's probably fine. I just took it from some example somewhere.

> 
>> 
>>> 
>>>> {
>>>> 	let df = DateFormatter()
>>>> 	df.dateFormat = "yyyy-MM-dd HH:mm:ss.SSS"
>>>> 	let time = df.string(from: Date())
>>>> 	
>>>> 	let file = (inFile as NSString).lastPathComponent
>>>> 	print("\(time) \(file):\(inLine)    \(inMsg)”)
>>> 
>>> Try \(inMsg ?? “nil”).
>> 
>> No, this is missing the point. I don't want to have to write this everywhere. I just want to tell the compiler not to issue the warning in these cases, much in the way you can tell the compiler to check printf format specifiers.
> 
> The fundamental issue here is that printing an Optional is probably not what you want to do, since it will print Optional(“your wrapped value”). If this is what you want, you will need to be explicit with String(describing:); if not, then use the nil coalescing operator to fallback to a value you want. You can also try guaranteeing that the value is not an optional by unwrapping it.

What I'm trying to avoid is dealing with it at the call site. I have to do that every time, and for printing of debug messages, "Optional()" is fine (although I have a proposal in mind to address that, too; I'd much rather just see "nil")



-- 
Rick Mann
rmann at latencyzero.com