test/std/utilities/memory/allocator.traits/allocator.traits.types/rebind_alloc.pass.cpp

//===----------------------------------------------------------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

// <memory>

// template <class Alloc>
// struct allocator_traits
// {
//     template <class T> using rebind_alloc  = Alloc::rebind<U>::other | Alloc<T, Args...>;
//     ...
// };

#include <memory>
#include <type_traits>

template <class T>
struct ReboundA {};

template <class T>
struct A
{
    typedef T value_type;

    template <class U> struct rebind {typedef ReboundA<U> other;};
};

template <class T, class U>
struct ReboundB {};

template <class T, class U>
struct B
{
    typedef T value_type;

    template <class V> struct rebind {typedef ReboundB<V, U> other;};
};

template <class T>
struct C
{
    typedef T value_type;
};

template <class T, class U>
struct D
{
    typedef T value_type;
};

template <class T>
struct E
{
    typedef T value_type;

    template <class U> struct rebind {typedef ReboundA<U> otter;};
};

int main()
{
#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
    static_assert((std::is_same<std::allocator_traits<A<char> >::rebind_alloc<double>, ReboundA<double> >::value), "");
    static_assert((std::is_same<std::allocator_traits<B<int, char> >::rebind_alloc<double>, ReboundB<double, char> >::value), "");
    static_assert((std::is_same<std::allocator_traits<C<char> >::rebind_alloc<double>, C<double> >::value), "");
    static_assert((std::is_same<std::allocator_traits<D<int, char> >::rebind_alloc<double>, D<double, char> >::value), "");
    static_assert((std::is_same<std::allocator_traits<E<char> >::rebind_alloc<double>, E<double> >::value), "");
#else  // _LIBCPP_HAS_NO_TEMPLATE_ALIASES
    static_assert((std::is_same<std::allocator_traits<A<char> >::rebind_alloc<double>::other, ReboundA<double> >::value), "");
    static_assert((std::is_same<std::allocator_traits<B<int, char> >::rebind_alloc<double>::other, ReboundB<double, char> >::value), "");
    static_assert((std::is_same<std::allocator_traits<C<char> >::rebind_alloc<double>::other, C<double> >::value), "");
    static_assert((std::is_same<std::allocator_traits<D<int, char> >::rebind_alloc<double>::other, D<double, char> >::value), "");
    static_assert((std::is_same<std::allocator_traits<E<char> >::rebind_alloc<double>::other, E<double> >::value), "");
#endif  // _LIBCPP_HAS_NO_TEMPLATE_ALIASES
}