third_party/llvm-project/libcxx/test/std/utilities/utility/mem.res/mem.poly.allocator.class/mem.poly.allocator.ctor/default.pass.cpp

//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

// UNSUPPORTED: c++03, c++11, c++14
// XFAIL: availability-pmr-missing

// test_memory_resource requires RTTI for dynamic_cast
// UNSUPPORTED: no-rtti

// <memory_resource>

// template <class T> class polymorphic_allocator

// polymorphic_allocator<T>::polymorphic_allocator() noexcept

#include <memory_resource>
#include <cassert>
#include <type_traits>

#include "test_std_memory_resource.h"

int main(int, char**) {
  {
    static_assert(std::is_nothrow_default_constructible<std::pmr::polymorphic_allocator<void>>::value,
                  "Must me nothrow default constructible");
  }
  {
    // test that the allocator gets its resource from get_default_resource
    TestResource R1(42);
    std::pmr::set_default_resource(&R1);

    typedef std::pmr::polymorphic_allocator<void> A;
    A const a;
    assert(a.resource() == &R1);

    std::pmr::set_default_resource(nullptr);
    A const a2;
    assert(a.resource() == &R1);
    assert(a2.resource() == std::pmr::new_delete_resource());
  }

  return 0;
}