base/cxx20_is_constant_evaluated.h

   1 // Copyright 2022 The Chromium Authors
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef BASE_CXX20_IS_CONSTANT_EVALUATED_H_
   6 #define BASE_CXX20_IS_CONSTANT_EVALUATED_H_
   7
   8 namespace base {
   9
  10 // Implementation of C++20's std::is_constant_evaluated.
  11 //
  12 // References:
  13 // - https://en.cppreference.com/w/cpp/types/is_constant_evaluated
  14 // - https://wg21.link/meta.const.eval
  15 constexpr bool is_constant_evaluated() noexcept {
  16   return __builtin_is_constant_evaluated();
  17 }
  18
  19 }  // namespace base
  20
  21 #endif  // BASE_CXX20_IS_CONSTANT_EVALUATED_H_