bb9ca6d0bf
Summary: This was voted into C++20 in San Diego. Note that there was a revision D0318R2 which did include unwrap_reference_t, but we mistakingly voted P0318R1 into the C++20 Working Draft (which does not include unwrap_reference_t). This patch implements D0318R2, which is what we'll end up with in the Working Draft once this mistake has been fixed. Reviewers: EricWF, mclow.lists Subscribers: christof, dexonsmith, libcxx-commits Differential Revision: https://reviews.llvm.org/D54485 llvm-svn: 348138
52 lines
1.2 KiB
C++
52 lines
1.2 KiB
C++
//===----------------------------------------------------------------------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is dual licensed under the MIT and the University of Illinois Open
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// Source Licenses. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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// <functional>
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//
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// template <class T>
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// struct unwrap_reference;
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//
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// template <class T>
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// using unwrap_reference_t = typename unwrap_reference<T>::type;
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// UNSUPPORTED: c++98, c++03, c++11, c++14, c++17
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#include <functional>
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#include <type_traits>
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template <typename T, typename Expected>
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void check_equal() {
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static_assert(std::is_same_v<typename std::unwrap_reference<T>::type, Expected>);
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static_assert(std::is_same_v<typename std::unwrap_reference<T>::type, std::unwrap_reference_t<T>>);
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}
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template <typename T>
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void check() {
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check_equal<T, T>();
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check_equal<T&, T&>();
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check_equal<T const, T const>();
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check_equal<T const&, T const&>();
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check_equal<std::reference_wrapper<T>, T&>();
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check_equal<std::reference_wrapper<T const>, T const&>();
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}
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struct T { };
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int main() {
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check<T>();
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check<int>();
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check<float>();
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check<T*>();
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check<int*>();
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check<float*>();
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}
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