possible "solution" for ufcs

[Monkol]

On Mon, 06 Jun 2011 22:00:13 +0300, Steven Schveighoffer  
<schveiguy at yahoo.com> wrote:

> Someone wrote a very compelling argument for ufcs (uniform function call  
> syntax) for ranges, and that is, given a slew of range functions, and a  
> slew of ranges, it is nice to use a fluent programming syntax to specify  
> wrappers for ranges without having to extend each range type.  For  
> example:
>
> take(10,stride(2,cycle([3,2,5,3])));
>
> vs.
>
> [3,2,5,3].cycle().stride(2).take(10);
>
> And I thought damn it would be nice if ranges could implement ufcs, but  
> other types that you didn't want to allow infinite extendability could  
> avoid it.  That gave me an idea :)
>
>
> import std.stdio;
>
> struct ufcs
> {
>      auto opDispatch(string name, T...)(T args) // appropriate if  
> compiles constraint here
>      {
>          mixin("return ." ~ name ~ "(this, args);");
>      }
> }
>
> int foo(ufcs x, int y)
> {
>      writefln("it works! %d", y);
>      return y+1;
> }
>
> void main()
> {
>      ufcs u;
>      auto x = u.foo(1);
>      assert(x == 2);
> }
>
> And it does indeed work (2.053)...
>
> So we can have ufcs without any changes to the compiler, and we also  
> make it a *choice* for people who don't want to allow infinite  
> extendability, and don't want to deal with possible compiler ambiguities.
>
> The opDispatch could even be a mixin itself (I think).
>
> What do you think?
>
> -Steve


what this code must to do?