[Issue 1839] Give D a modern varargs system that allows forwarding

[d-bugmail at puremagic.com]

http://d.puremagic.com/issues/show_bug.cgi?id=1839





------- Comment #10 from wbaxter at gmail.com  2008-02-15 04:58 -------
(In reply to comment #8)
> I misunderstood your initial code sample. In fact that's a simpler problem:
> 
> import std.stdio;
> 
> void before() {}
> void after() {}
> 
> void fn(...)
> {
>     foreach (i; 0 .. _arguments.length)
>     {
>         _arguments[i].print;
>     }
>     if (_arguments[0] == typeid(int))
>     {
>         int j = *cast(int *)_argptr;
>         writeln(j);
>     }
> }
> 
> void wrapsFn(T...)(T args)
> {
>     before();
>     scope(exit) after();
>     fn(args);
> }
> 
> void main()
> {
>     wrapsFn(2, 42, "a");
> }
> 

Ok, but it's no longer a function.  I can't do with wrapFn the same things I
can do with a regular function, namely taking it's address and passing that
around or calling through it later.  If there were a simple and efficient way
to convert the wrapsFn template into a function pointer then I'd be satisfied
with that solution.


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