Typesafe variadics in any position

[simendsjo]

On Tuesday, 26 February 2013 at 20:52:46 UTC, Steven 
Schveighoffer wrote:
> On Tue, 26 Feb 2013 15:36:11 -0500, Andrej Mitrovic 
> <andrej.mitrovich at gmail.com> wrote:
>
>> On Tuesday, 26 February 2013 at 20:29:51 UTC, Steven 
>> Schveighoffer wrote:
>>> Would it be something people want?
>>
>> Yes. Also related: 
>> http://d.puremagic.com/issues/show_bug.cgi?id=8687
>>
>> One extremely common and important use-case of allowing it is 
>> this:
>>
>> foo(string[] args..., string file = __FILE__, size_t line = 
>> __LINE__);
>>
>> Right now as soon as you introduce variadics you can forget 
>> about using __FILE__/__LINE__ at runtime (unless you resort to 
>> some inner-template tricks, but that only works in some cases 
>> methinks, probably not at runtime).
>
> Well, except that example wouldn't work :)
>
> This would though:
>
> foo(string[] args..., size_t line = __LINE__, string file = 
> __FILE__);
>
> Excellent use case though!
>
> -Steve

or use a new struct
struct SourcePos {
   string file;
   size_t line;
}
foo(string[] args..., SourcePos pos = SourcePos(__FILE__, 
__LINE__));