e16f2cb678
Summary: LWG2510 makes tag types like allocator_arg_t explicitly default constructible instead of implicitly default constructible. It also makes the constructors for std::pair and std::tuple conditionally explicit based on the explicit-ness of the default constructibility for the pair/tuple's elements. This was previously committed as r372777 and reverted in r372832 due to the commit breaking LLVM's build in C++14 mode. This issue has now been addressed. Reviewers: mclow.lists Subscribers: christof, jkorous, dexonsmith, libcxx-commits Tags: #libc Differential Revision: https://reviews.llvm.org/D65161 llvm-svn: 372983
57 lines
1.5 KiB
C++
57 lines
1.5 KiB
C++
//===----------------------------------------------------------------------===//
|
|
//
|
|
// 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
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
// <utility>
|
|
|
|
// template <class T1, class T2> struct pair
|
|
|
|
// explicit(see-below) constexpr pair();
|
|
|
|
// NOTE: The SFINAE on the default constructor is tested in
|
|
// default-sfinae.pass.cpp
|
|
|
|
|
|
#include <utility>
|
|
#include <type_traits>
|
|
#include <cassert>
|
|
|
|
#include "test_macros.h"
|
|
#include "archetypes.h"
|
|
|
|
int main(int, char**)
|
|
{
|
|
{
|
|
typedef std::pair<float, short*> P;
|
|
P p;
|
|
assert(p.first == 0.0f);
|
|
assert(p.second == nullptr);
|
|
}
|
|
#if TEST_STD_VER >= 11
|
|
{
|
|
typedef std::pair<float, short*> P;
|
|
constexpr P p;
|
|
static_assert(p.first == 0.0f, "");
|
|
static_assert(p.second == nullptr, "");
|
|
}
|
|
{
|
|
using NoDefault = ImplicitTypes::NoDefault;
|
|
using P = std::pair<int, NoDefault>;
|
|
static_assert(!std::is_default_constructible<P>::value, "");
|
|
using P2 = std::pair<NoDefault, int>;
|
|
static_assert(!std::is_default_constructible<P2>::value, "");
|
|
}
|
|
{
|
|
struct Base { };
|
|
struct Derived : Base { protected: Derived() = default; };
|
|
static_assert(!std::is_default_constructible<std::pair<Derived, int> >::value, "");
|
|
}
|
|
#endif
|
|
|
|
return 0;
|
|
}
|