1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
base / numerics / integral_constant_like.h [blame]
// Copyright 2024 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef BASE_NUMERICS_INTEGRAL_CONSTANT_LIKE_H_
#define BASE_NUMERICS_INTEGRAL_CONSTANT_LIKE_H_
#include <concepts>
#include <type_traits>
namespace base {
// Exposition-only concept from [span.syn]
template <typename T>
concept IntegralConstantLike =
std::is_integral_v<decltype(T::value)> &&
!std::is_same_v<bool, std::remove_const_t<decltype(T::value)>> &&
std::convertible_to<T, decltype(T::value)> &&
std::equality_comparable_with<T, decltype(T::value)> &&
std::bool_constant<T() == T::value>::value &&
std::bool_constant<static_cast<decltype(T::value)>(T()) == T::value>::value;
} // namespace base
#endif // BASE_NUMERICS_INTEGRAL_CONSTANT_LIKE_H_