Re: 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.mitrov...@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__));