Stroustrup's talk on C++0x

[Bill Baxter]

Walter Bright wrote:
> Bill Baxter wrote:
>> Walter Bright wrote:
>>> Bill Baxter wrote:
>>
>>>> but some are also available in g++ now, I believe.  And there are 
>>>> some features slated for  C++ 09 that aren't on the roadmap for D at 
>>>> all (like concepts
>>>
>>> Concepts aren't a whole lot more than interface specialization, which 
>>> is already supported in D.
>>
>> I'm not sure what you mean by that, but the feature that I liked most 
>> about it is interface checking.  So
>> A) Being able to document someplace that if you want to use my 
>> KewlContainer you must implement the KewlIteratorConcept which means, 
>> say, you support opPostInc() and opSlice() (for dereferencing as x[]).
>> and then once that is documented
>> B) being able to say that my class implements that concept and have 
>> the compiler check that indeed it does.
>>
>> I suppose there may be some way to do all that in current D,
> 
> Yup:
> 
> interface KewlIteratorConcept
> {
>     T opPostInc();
>     U opSlice();
> }
> 
> class KewlContainer : KewlIteratorConcept
> {
>     T opPostInc() { ... }
>     U opSlice() { ... }
> }
> 
> class WrongContainer
> {
> }
> 
> template Foo(T : KewlIteratorConcept) { ... }
> 
> KewlContainer k;
> WrongContainer w;
> 
> Foo!(k);    // ok
> Foo!(w);    // error, w is not a KewlIteratorConcept

Ok, but does that work if you want it to work with a built-in type too? 
  Will a float be recognized as supporting opPostInc?

--bb