Home | History | Annotate | Download | only in allocator.traits.types 
      1 //===----------------------------------------------------------------------===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is dual licensed under the MIT and the University of Illinois Open
      6 // Source Licenses. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 
     10 // <memory>
     11 
     12 // template <class Alloc>
     13 // struct allocator_traits
     14 // {
     15 //     template <class T> using rebind_alloc  = Alloc::rebind<U>::other | Alloc<T, Args...>;
     16 //     ...
     17 // };
     18 
     19 #include <memory>
     20 #include <type_traits>
     21 
     22 template <class T>
     23 struct ReboundA {};
     24 
     25 template <class T>
     26 struct A
     27 {
     28     typedef T value_type;
     29 
     30     template <class U> struct rebind {typedef ReboundA<U> other;};
     31 };
     32 
     33 template <class T, class U>
     34 struct ReboundB {};
     35 
     36 template <class T, class U>
     37 struct B
     38 {
     39     typedef T value_type;
     40 
     41     template <class V> struct rebind {typedef ReboundB<V, U> other;};
     42 };
     43 
     44 template <class T>
     45 struct C
     46 {
     47     typedef T value_type;
     48 };
     49 
     50 template <class T, class U>
     51 struct D
     52 {
     53     typedef T value_type;
     54 };
     55 
     56 template <class T>
     57 struct E
     58 {
     59     typedef T value_type;
     60 
     61     template <class U> struct rebind {typedef ReboundA<U> otter;};
     62 };
     63 
     64 int main()
     65 {
     66 #ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
     67     static_assert((std::is_same<std::allocator_traits<A<char> >::rebind_alloc<double>, ReboundA<double> >::value), "");
     68     static_assert((std::is_same<std::allocator_traits<B<int, char> >::rebind_alloc<double>, ReboundB<double, char> >::value), "");
     69     static_assert((std::is_same<std::allocator_traits<C<char> >::rebind_alloc<double>, C<double> >::value), "");
     70     static_assert((std::is_same<std::allocator_traits<D<int, char> >::rebind_alloc<double>, D<double, char> >::value), "");
     71     static_assert((std::is_same<std::allocator_traits<E<char> >::rebind_alloc<double>, E<double> >::value), "");
     72 #else  // _LIBCPP_HAS_NO_TEMPLATE_ALIASES
     73     static_assert((std::is_same<std::allocator_traits<A<char> >::rebind_alloc<double>::other, ReboundA<double> >::value), "");
     74     static_assert((std::is_same<std::allocator_traits<B<int, char> >::rebind_alloc<double>::other, ReboundB<double, char> >::value), "");
     75     static_assert((std::is_same<std::allocator_traits<C<char> >::rebind_alloc<double>::other, C<double> >::value), "");
     76     static_assert((std::is_same<std::allocator_traits<D<int, char> >::rebind_alloc<double>::other, D<double, char> >::value), "");
     77     static_assert((std::is_same<std::allocator_traits<E<char> >::rebind_alloc<double>::other, E<double> >::value), "");
     78 #endif  // _LIBCPP_HAS_NO_TEMPLATE_ALIASES
     79 }
     80