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3f10018902
These functions are key to allowing the use of rvalues and variadics
in C++03 mode. Everything works the same as in C++11, except for one
tangentially related case:
struct T {
T(T &&) = default;
};
In C++11, T has a deleted copy constructor. But in C++03 Clang gives
it both a move and a copy constructor. This seems reasonable enough
given the extensions it's using.
The other changes in this patch were the minimal set required
to keep the tests passing after the move/forward change. Most notably
the removal of the `__rv<unique_ptr>` hack that was present
in an attempt to make unique_ptr move only without language support.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@364063 91177308-0d34-0410-b5e6-96231b3b80d8
73 lines
2.1 KiB
C++
73 lines
2.1 KiB
C++
//===----------------------------------------------------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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// <utility>
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// template <class T>
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// typename conditional
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// <
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// !is_nothrow_move_constructible<T>::value && is_copy_constructible<T>::value,
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// const T&,
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// T&&
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// >::type
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// move_if_noexcept(T& x);
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#include <utility>
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#include "test_macros.h"
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class A
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{
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A(const A&);
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A& operator=(const A&);
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public:
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A() {}
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A(A&&) {}
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};
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struct legacy
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{
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legacy() {}
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legacy(const legacy&);
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};
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int main(int, char**)
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{
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int i = 0;
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const int ci = 0;
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legacy l;
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A a;
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const A ca;
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#if TEST_STD_VER >= 11
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static_assert((std::is_same<decltype(std::move_if_noexcept(i)), int&&>::value), "");
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static_assert((std::is_same<decltype(std::move_if_noexcept(ci)), const int&&>::value), "");
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static_assert((std::is_same<decltype(std::move_if_noexcept(a)), A&&>::value), "");
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static_assert((std::is_same<decltype(std::move_if_noexcept(ca)), const A&&>::value), "");
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static_assert((std::is_same<decltype(std::move_if_noexcept(l)), const legacy&>::value), "");
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#else // C++ < 11
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// In C++03 we don't have noexcept so we can never move :-(
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static_assert((std::is_same<decltype(std::move_if_noexcept(i)), const int&>::value), "");
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static_assert((std::is_same<decltype(std::move_if_noexcept(ci)), const int&>::value), "");
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static_assert((std::is_same<decltype(std::move_if_noexcept(a)), const A&>::value), "");
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static_assert((std::is_same<decltype(std::move_if_noexcept(ca)), const A&>::value), "");
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static_assert((std::is_same<decltype(std::move_if_noexcept(l)), const legacy&>::value), "");
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#endif
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#if TEST_STD_VER > 11
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constexpr int i1 = 23;
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constexpr int i2 = std::move_if_noexcept(i1);
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static_assert(i2 == 23, "" );
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#endif
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return 0;
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}
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