libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.members/allocate.pass.cpp

   1 //===----------------------------------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 // <memory>
  10
  11 // template <class Alloc>
  12 // struct allocator_traits
  13 // {
  14 //     static constexpr pointer allocate(allocator_type& a, size_type n);
  15 //     ...
  16 // };
  17
  18 #include <memory>
  19 #include <cstdint>
  20 #include <cassert>
  21
  22 #include "test_macros.h"
  23 #include "incomplete_type_helper.h"
  24
  25 template <class T>
  26 struct A
  27 {
  28     typedef T value_type;
  29
  30     TEST_CONSTEXPR_CXX20 A() {}
  31
  32     TEST_CONSTEXPR_CXX20 value_type* allocate(std::size_t n)
  33     {
  34         assert(n == 10);
  35         return &storage;
  36     }
  37
  38     value_type storage;
  39 };
  40
  41 TEST_CONSTEXPR_CXX20 bool test()
  42 {
  43     {
  44         A<int> a;
  45         assert(std::allocator_traits<A<int> >::allocate(a, 10) == &a.storage);
  46     }
  47     {
  48         typedef A<IncompleteHolder*> Alloc;
  49         Alloc a;
  50         assert(std::allocator_traits<Alloc>::allocate(a, 10) == &a.storage);
  51     }
  52
  53     return true;
  54 }
  55
  56 int main(int, char**)
  57 {
  58     test();
  59 #if TEST_STD_VER > 17
  60     static_assert(test());
  61 #endif
  62     return 0;
  63 }