<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div><br class=""><blockquote type="cite" class=""><div class=""><span style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; float: none; display: inline !important;" class="">It is a rare case for a result of a function to be unused – and most often it's caused by programmer having too little knowledge of the API.<span class="Apple-converted-space"> </span></span></div></blockquote></div>I don't think this is a real life problem. When you have a class with something like "append" that doesn't change the receiver but returns a new object, it could be a valuable hint, but I don't like systems which assume that their users don't know what they are doing; and if this is actually the case, you are fighting a tough battle where a little warning wont help.<div class=""><br class=""></div><div class="">Please also note that ignoring a non-void return value can be absolutely ok in many situations: One example is returning self instead of useless void, which allows to build fluent interfaces - just because Cocoa didn't adopt the concept of method chaining from Smalltalk, it is still a interesting pattern which is used by other frameworks.</div><div class=""><br class=""></div><div class="">Imho warnings should be reserved for things that can be dangerous, and not to educate programmers...</div></body></html>