On 08/10/12 12:16, Lorenzo Caminiti wrote: <snip>
2) Another valid argument for requires is that the compiler will give the algorithm implementer an error if he/she uses the type in a way that doesn't model the concept (as Matt pointed out):
template< typename T > requires EqualityComparable<T> bool equal ( T const& a, Tconst& b) { T x = a; // compiler error: T is not CopyConstructible, it's just EqualityComparable ... }
Unfortunately, I don't think I can do this in a lib :( Can I? Does Boost.Generic provide such errors?
One way might be to form an archetype and instantiate the template with it. I think Boost.Generic does (or at least aimed to) support the creation of archetypes, but I doubt that it does this. I suspect such an approach would be fraught with complications, but it might be workable. John