possible "solution" for ufcs

[KennyTM~]

On Jun 7, 11 03:22, Monkol wrote:
> 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
>
>
> may be you lost symbol "!" when call template opDispatch!(string name,
> T...)(T args)

No Steven is correct. You don't need the '!' before the template parameters.