eec04092d6
Implement the resolution of LWG2993. Replace a deleted constructor with a constructor that SFINAEs away in appropriate circumstances. Also, now that the constructor is templated, we must have an explicit deduction guide to make CTAD work. Some tests have been merged in from Agustín Bergé's D40259. Differential Revision: https://reviews.llvm.org/D92725
81 lines
1.6 KiB
C++
81 lines
1.6 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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// <functional>
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// reference_wrapper
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// reference_wrapper& operator=(const reference_wrapper<T>& x);
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#include <functional>
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#include <cassert>
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#include "test_macros.h"
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class functor1
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{
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};
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struct convertible_to_int_ref {
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int val = 0;
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operator int&() { return val; }
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operator int const&() const { return val; }
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};
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template <class T>
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void
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test(T& t)
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{
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std::reference_wrapper<T> r(t);
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T t2 = t;
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std::reference_wrapper<T> r2(t2);
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r2 = r;
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assert(&r2.get() == &t);
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}
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void f() {}
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void g() {}
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void
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test_function()
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{
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std::reference_wrapper<void ()> r(f);
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std::reference_wrapper<void ()> r2(g);
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r2 = r;
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assert(&r2.get() == &f);
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}
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int main(int, char**)
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{
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void (*fp)() = f;
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test(fp);
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test_function();
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functor1 f1;
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test(f1);
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int i = 0;
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test(i);
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const int j = 0;
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test(j);
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#if TEST_STD_VER >= 11
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convertible_to_int_ref convi;
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test(convi);
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convertible_to_int_ref const convic;
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test(convic);
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{
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using Ref = std::reference_wrapper<int>;
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static_assert((std::is_assignable<Ref&, int&>::value), "");
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static_assert((!std::is_assignable<Ref&, int>::value), "");
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static_assert((!std::is_assignable<Ref&, int&&>::value), "");
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}
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#endif
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return 0;
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}
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