Subject: Re: [boost] Tick: Trait instrospection and concepts library now for C++11
From: Vicente J. Botet Escriba (vicente.botet_at_[hidden])
Date: 2014-06-05 02:37:38
Le 05/06/14 07:53, paul Fultz a écrit :
> Hi,
>
> I've just update the Tick library to support C++11 compilers including support
> for gcc 4.6:
>
> https://github.com/pfultz2/Tick
>
> To support gcc 4.6 an additional `TICK_RETURNS` macro was added. So while this
> can be written for gcc 4.7 or later:
>
> TICK_TRAIT(is_incrementable)
> {
> template<class T>
> auto requires_(T&& x) -> TICK_VALID(
> returns<int>(x++)
> );
> };
>
> This can be written in order to support gcc 4.6:
>
> TICK_TRAIT(is_incrementable)
> {
> template<class T>
> auto requires_(T&& x) -> TICK_VALID(
> TICK_RETURNS(x++, int)
> );
> };
>
> Of course, the macro is optional and only needed to support older compilers.
>
> Any other feedback would be appreciated.
>
>
Hi,
Does your library define just traits or try to emulate Concept Lite?
In this post concepts_at_[hidden] "[concepts] Can Concepts Lite be used
to conditionally disable a copy constructor?" there are a couple of
questions related to your library.
* Can these traits be used to conditionally disable a constructors? an
assignment?
class NonCopyable
{
NonCopyable(NonCopyable const&) = delete;
};
template <typename T>
class wrapper
{
wrapper(const wrapper&)
requires std::is_copy_constructible<T>::value {}
};
* Can non-template members of template class be overloaded by only
requires clause? I mean is the following examples correct (assuming that
C1 and C2 are concepts):
template<typename T>
struct A
{
A(const A&) requires C1<T> { /*...*/ };
A(const A&) requires C2<T> { /*...*/ };
};
How the refinements plays on this concern?
What are the limitations respect ConceptLite?
Best,
Vicente