//===----------------------------------------------------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//

// <string>

// explicit basic_string(const Allocator& a = Allocator()); // constexpr since C++20

#include <string>
#include <cassert>

#include "test_macros.h"
#include "test_allocator.h"
#include "min_allocator.h"

template <class S>
TEST_CONSTEXPR_CXX20 void test() {
  {
#if TEST_STD_VER > 14
    static_assert((noexcept(S{})), "");
#elif TEST_STD_VER >= 11
    static_assert((noexcept(S()) == noexcept(typename S::allocator_type())), "");
#endif
    S s;
    LIBCPP_ASSERT(s.__invariants());
    assert(s.data());
    assert(s.size() == 0);
    assert(s.capacity() >= s.size());
    assert(s.get_allocator() == typename S::allocator_type());
  }
  {
#if TEST_STD_VER > 14
    static_assert((noexcept(S{typename S::allocator_type{}})), "");
#elif TEST_STD_VER >= 11
    static_assert((noexcept(S(typename S::allocator_type())) ==
                   std::is_nothrow_copy_constructible<typename S::allocator_type>::value),
                  "");
#endif
    S s(typename S::allocator_type(5));
    LIBCPP_ASSERT(s.__invariants());
    assert(s.data());
    assert(s.size() == 0);
    assert(s.capacity() >= s.size());
    assert(s.get_allocator() == typename S::allocator_type(5));
  }
}

#if TEST_STD_VER >= 11

template <class S>
TEST_CONSTEXPR_CXX20 void test2() {
  {
#  if TEST_STD_VER > 14
    static_assert((noexcept(S{})), "");
#  elif TEST_STD_VER >= 11
    static_assert((noexcept(S()) == noexcept(typename S::allocator_type())), "");
#  endif
    S s;
    LIBCPP_ASSERT(s.__invariants());
    assert(s.data());
    assert(s.size() == 0);
    assert(s.capacity() >= s.size());
    assert(s.get_allocator() == typename S::allocator_type());
  }
  {
#  if TEST_STD_VER > 14
    static_assert((noexcept(S{typename S::allocator_type{}})), "");
#  elif TEST_STD_VER >= 11
    static_assert((noexcept(S(typename S::allocator_type())) ==
                   std::is_nothrow_copy_constructible<typename S::allocator_type>::value),
                  "");
#  endif
    S s(typename S::allocator_type{});
    LIBCPP_ASSERT(s.__invariants());
    assert(s.data());
    assert(s.size() == 0);
    assert(s.capacity() >= s.size());
    assert(s.get_allocator() == typename S::allocator_type());
  }
}

#endif

TEST_CONSTEXPR_CXX20 bool test() {
  test<std::basic_string<char, std::char_traits<char>, test_allocator<char> > >();
#if TEST_STD_VER >= 11
  test2<std::basic_string<char, std::char_traits<char>, min_allocator<char> > >();
  test2<std::basic_string<char, std::char_traits<char>, explicit_allocator<char> > >();
#endif

  return true;
}

int main(int, char**) {
  test();
#if TEST_STD_VER > 17
  static_assert(test());
#endif

  return 0;
}