a061d4d5ce
Previously, SFINAE constraints and exception specification propagation were missing in the return type of libc++'s `std::mem_fn`. The requirements on expression-equivalence (or even plain "equivalent" in pre-C++20 specification) in [func.memfn] are actually requiring them. This PR adds the missed stuffs. Fixes #86043. Drive-by changes: - removing no longer used `__invoke_return`, - updating synopsis comments in several files, and - merging several test files for `mem_fn` into one.
45 lines
867 B
C++
45 lines
867 B
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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// template<class R, class T> constexpr unspecified mem_fn(R T::*) noexcept; // constexpr in C++20
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#include <functional>
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#include <cassert>
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struct A
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{
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double data_;
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};
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template <class F>
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void
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test(F f)
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{
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{
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A a;
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f(a) = 5;
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assert(a.data_ == 5);
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A* ap = &a;
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f(ap) = 6;
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assert(a.data_ == 6);
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const A* cap = ap;
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assert(f(cap) == f(ap));
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f(cap) = 7;
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}
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}
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int main(int, char**)
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{
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test(std::mem_fn(&A::data_));
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return 0;
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}
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