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//===----------------------------------------------------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
// UNSUPPORTED: c++03, c++11, c++14, c++17
// <type_traits>
// constexpr bool is_constant_evaluated() noexcept; // C++20
#include <type_traits>
#include <cassert>
#include "test_macros.h"
#ifndef __cpp_lib_is_constant_evaluated
#if TEST_HAS_BUILTIN(__builtin_is_constant_evaluated)
# error __cpp_lib_is_constant_evaluated should be defined
#endif
#endif
// Disable the tautological constant evaluation warnings for this test,
// because it's explicitly testing those cases.
#if TEST_HAS_WARNING("-Wconstant-evaluated") && defined(__clang__)
#pragma clang diagnostic ignored "-Wconstant-evaluated"
#endif
template <bool> struct InTemplate {};
int main(int, char**)
{
#ifdef __cpp_lib_is_constant_evaluated
#ifdef TEST_COMPILER_C1XX
#pragma warning(push)
#pragma warning(disable: 5063) // 'std::is_constant_evaluated' always evaluates to true in manifestly constant-evaluated expressions
#endif // TEST_COMPILER_C1XX
// Test the signature
{
ASSERT_SAME_TYPE(decltype(std::is_constant_evaluated()), bool);
ASSERT_NOEXCEPT(std::is_constant_evaluated());
constexpr bool p = std::is_constant_evaluated();
assert(p);
}
// Test the return value of the builtin for basic sanity only. It's the
// compiler's job to test the builtin for correctness.
{
static_assert(std::is_constant_evaluated(), "");
bool p = std::is_constant_evaluated();
assert(!p);
ASSERT_SAME_TYPE(InTemplate<std::is_constant_evaluated()>, InTemplate<true>);
static int local_static = std::is_constant_evaluated() ? 42 : -1;
assert(local_static == 42);
}
#ifdef TEST_COMPILER_C1XX
#pragma warning(pop)
#endif // TEST_COMPILER_C1XX
#endif // __cpp_lib_is_constant_evaluated
return 0;
}
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