| //===----------------------------------------------------------------------===// |
| // |
| // 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 |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef _LIBCPP___UTILITY_CONSTANT_WRAPPER_H |
| #define _LIBCPP___UTILITY_CONSTANT_WRAPPER_H |
| |
| #include <__config> |
| #include <__cstddef/size_t.h> |
| #include <__functional/invoke.h> |
| #include <__type_traits/invoke.h> |
| #include <__type_traits/is_constructible.h> |
| #include <__type_traits/is_same.h> |
| #include <__type_traits/remove_cvref.h> |
| #include <__utility/declval.h> |
| #include <__utility/forward.h> |
| #include <__utility/integer_sequence.h> |
| |
| #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) |
| # pragma GCC system_header |
| #endif |
| |
| _LIBCPP_BEGIN_NAMESPACE_STD |
| |
| #if _LIBCPP_STD_VER >= 26 |
| |
| template <auto _Xp, class = remove_cvref_t<decltype(_Xp)>> |
| struct constant_wrapper; |
| |
| template <class _Tp> |
| concept __constexpr_param = requires { typename constant_wrapper<_Tp::value>; }; |
| |
| template <auto _Xp> |
| constexpr auto cw = constant_wrapper<_Xp>{}; |
| |
| struct __cw_operators { |
| // unary operators |
| template <__constexpr_param _Tp> |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI friend constexpr auto operator+(_Tp) noexcept -> constant_wrapper<(+_Tp::value)> { |
| return {}; |
| } |
| template <__constexpr_param _Tp> |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI friend constexpr auto operator-(_Tp) noexcept -> constant_wrapper<(-_Tp::value)> { |
| return {}; |
| } |
| template <__constexpr_param _Tp> |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI friend constexpr auto operator~(_Tp) noexcept -> constant_wrapper<(~_Tp::value)> { |
| return {}; |
| } |
| template <__constexpr_param _Tp> |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI friend constexpr auto operator!(_Tp) noexcept -> constant_wrapper<(!_Tp::value)> { |
| return {}; |
| } |
| template <__constexpr_param _Tp> |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI friend constexpr auto operator&(_Tp) noexcept -> constant_wrapper<(&_Tp::value)> { |
| return {}; |
| } |
| template <__constexpr_param _Tp> |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI friend constexpr auto operator*(_Tp) noexcept -> constant_wrapper<(*_Tp::value)> { |
| return {}; |
| } |
| |
| // binary operators |
| template <__constexpr_param _Lp, __constexpr_param _Rp> |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI friend constexpr auto operator+(_Lp, _Rp) noexcept |
| -> constant_wrapper<(_Lp::value + _Rp::value)> { |
| return {}; |
| } |
| template <__constexpr_param _Lp, __constexpr_param _Rp> |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI friend constexpr auto operator-(_Lp, _Rp) noexcept |
| -> constant_wrapper<(_Lp::value - _Rp::value)> { |
| return {}; |
| } |
| template <__constexpr_param _Lp, __constexpr_param _Rp> |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI friend constexpr auto operator*(_Lp, _Rp) noexcept |
| -> constant_wrapper<(_Lp::value * _Rp::value)> { |
| return {}; |
| } |
| template <__constexpr_param _Lp, __constexpr_param _Rp> |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI friend constexpr auto operator/(_Lp, _Rp) noexcept |
| -> constant_wrapper<(_Lp::value / _Rp::value)> { |
| return {}; |
| } |
| template <__constexpr_param _Lp, __constexpr_param _Rp> |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI friend constexpr auto operator%(_Lp, _Rp) noexcept |
| -> constant_wrapper<(_Lp::value % _Rp::value)> { |
| return {}; |
| } |
| |
| template <__constexpr_param _Lp, __constexpr_param _Rp> |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI friend constexpr auto operator<<(_Lp, _Rp) noexcept |
| -> constant_wrapper<(_Lp::value << _Rp::value)> { |
| return {}; |
| } |
| template <__constexpr_param _Lp, __constexpr_param _Rp> |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI friend constexpr auto operator>>(_Lp, _Rp) noexcept |
| -> constant_wrapper<(_Lp::value >> _Rp::value)> { |
| return {}; |
| } |
| template <__constexpr_param _Lp, __constexpr_param _Rp> |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI friend constexpr auto operator&(_Lp, _Rp) noexcept |
| -> constant_wrapper<(_Lp::value & _Rp::value)> { |
| return {}; |
| } |
| template <__constexpr_param _Lp, __constexpr_param _Rp> |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI friend constexpr auto operator|(_Lp, _Rp) noexcept |
| -> constant_wrapper<(_Lp::value | _Rp::value)> { |
| return {}; |
| } |
| template <__constexpr_param _Lp, __constexpr_param _Rp> |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI friend constexpr auto operator^(_Lp, _Rp) noexcept |
| -> constant_wrapper<(_Lp::value ^ _Rp::value)> { |
| return {}; |
| } |
| |
| template <__constexpr_param _Lp, __constexpr_param _Rp> |
| requires(!is_constructible_v<bool, decltype(_Lp::value)> || !is_constructible_v<bool, decltype(_Rp::value)>) |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI friend constexpr auto operator&&(_Lp, _Rp) noexcept |
| -> constant_wrapper<(_Lp::value && _Rp::value)> { |
| return {}; |
| } |
| template <__constexpr_param _Lp, __constexpr_param _Rp> |
| requires(!is_constructible_v<bool, decltype(_Lp::value)> || !is_constructible_v<bool, decltype(_Rp::value)>) |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI friend constexpr auto operator||(_Lp, _Rp) noexcept |
| -> constant_wrapper<(_Lp::value || _Rp::value)> { |
| return {}; |
| } |
| |
| // comparisons |
| template <__constexpr_param _Lp, __constexpr_param _Rp> |
| _LIBCPP_HIDE_FROM_ABI friend constexpr auto operator<=>(_Lp, _Rp) noexcept |
| -> constant_wrapper<(_Lp::value <=> _Rp::value)> { |
| return {}; |
| } |
| template <__constexpr_param _Lp, __constexpr_param _Rp> |
| _LIBCPP_HIDE_FROM_ABI friend constexpr auto operator<(_Lp, _Rp) noexcept |
| -> constant_wrapper<(_Lp::value < _Rp::value)> { |
| return {}; |
| } |
| template <__constexpr_param _Lp, __constexpr_param _Rp> |
| _LIBCPP_HIDE_FROM_ABI friend constexpr auto operator<=(_Lp, _Rp) noexcept |
| -> constant_wrapper<(_Lp::value <= _Rp::value)> { |
| return {}; |
| } |
| template <__constexpr_param _Lp, __constexpr_param _Rp> |
| _LIBCPP_HIDE_FROM_ABI friend constexpr auto operator==(_Lp, _Rp) noexcept |
| -> constant_wrapper<(_Lp::value == _Rp::value)> { |
| return {}; |
| } |
| template <__constexpr_param _Lp, __constexpr_param _Rp> |
| _LIBCPP_HIDE_FROM_ABI friend constexpr auto operator!=(_Lp, _Rp) noexcept |
| -> constant_wrapper<(_Lp::value != _Rp::value)> { |
| return {}; |
| } |
| template <__constexpr_param _Lp, __constexpr_param _Rp> |
| _LIBCPP_HIDE_FROM_ABI friend constexpr auto operator>(_Lp, _Rp) noexcept |
| -> constant_wrapper<(_Lp::value > _Rp::value)> { |
| return {}; |
| } |
| template <__constexpr_param _Lp, __constexpr_param _Rp> |
| _LIBCPP_HIDE_FROM_ABI friend constexpr auto operator>=(_Lp, _Rp) noexcept |
| -> constant_wrapper<(_Lp::value >= _Rp::value)> { |
| return {}; |
| } |
| |
| template <__constexpr_param _Lp, __constexpr_param _Rp> |
| friend auto operator,(_Lp, _Rp) = delete; |
| |
| template <__constexpr_param _Lp, __constexpr_param _Rp> |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI friend constexpr auto operator->*(_Lp, _Rp) noexcept |
| // TODO: Remove `auto` when all support versions of Clang have https://llvm.org/PR202693 fixed. |
| -> constant_wrapper<auto(_Lp::value->*_Rp::value)> { |
| return {}; |
| } |
| |
| // pseudo-mutators |
| template <__constexpr_param _Tp> |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator++(this _Tp) noexcept -> constant_wrapper<(++_Tp::value)> { |
| return {}; |
| } |
| template <__constexpr_param _Tp> |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator++(this _Tp, int) noexcept |
| -> constant_wrapper<(_Tp::value++)> { |
| return {}; |
| } |
| template <__constexpr_param _Tp> |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator--(this _Tp) noexcept -> constant_wrapper<(--_Tp::value)> { |
| return {}; |
| } |
| template <__constexpr_param _Tp> |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator--(this _Tp, int) noexcept |
| -> constant_wrapper<(_Tp::value--)> { |
| return {}; |
| } |
| |
| template <__constexpr_param _Tp, __constexpr_param _Rp> |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator+=(this _Tp, _Rp) noexcept |
| // TODO: Remove `auto` when all support versions of Clang have https://llvm.org/PR202693 fixed. |
| -> constant_wrapper<auto(_Tp::value += _Rp::value)> { |
| return {}; |
| } |
| template <__constexpr_param _Tp, __constexpr_param _Rp> |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator-=(this _Tp, _Rp) noexcept |
| // TODO: Remove `auto` when all support versions of Clang have https://llvm.org/PR202693 fixed. |
| -> constant_wrapper<auto(_Tp::value -= _Rp::value)> { |
| return {}; |
| } |
| template <__constexpr_param _Tp, __constexpr_param _Rp> |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator*=(this _Tp, _Rp) noexcept |
| // TODO: Remove `auto` when all support versions of Clang have https://llvm.org/PR202693 fixed. |
| -> constant_wrapper<auto(_Tp::value *= _Rp::value)> { |
| return {}; |
| } |
| template <__constexpr_param _Tp, __constexpr_param _Rp> |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator/=(this _Tp, _Rp) noexcept |
| // TODO: Remove `auto` when all support versions of Clang have https://llvm.org/PR202693 fixed. |
| -> constant_wrapper<auto(_Tp::value /= _Rp::value)> { |
| return {}; |
| } |
| template <__constexpr_param _Tp, __constexpr_param _Rp> |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator%=(this _Tp, _Rp) noexcept |
| // TODO: Remove `auto` when all support versions of Clang have https://llvm.org/PR202693 fixed. |
| -> constant_wrapper<auto(_Tp::value %= _Rp::value)> { |
| return {}; |
| } |
| template <__constexpr_param _Tp, __constexpr_param _Rp> |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator&=(this _Tp, _Rp) noexcept |
| // TODO: Remove `auto` when all support versions of Clang have https://llvm.org/PR202693 fixed. |
| -> constant_wrapper<auto(_Tp::value &= _Rp::value)> { |
| return {}; |
| } |
| template <__constexpr_param _Tp, __constexpr_param _Rp> |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator|=(this _Tp, _Rp) noexcept |
| // TODO: Remove `auto` when all support versions of Clang have https://llvm.org/PR202693 fixed. |
| -> constant_wrapper<auto(_Tp::value |= _Rp::value)> { |
| return {}; |
| } |
| template <__constexpr_param _Tp, __constexpr_param _Rp> |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator^=(this _Tp, _Rp) noexcept |
| // TODO: Remove `auto` when all support versions of Clang have https://llvm.org/PR202693 fixed. |
| -> constant_wrapper<auto(_Tp::value ^= _Rp::value)> { |
| return {}; |
| } |
| template <__constexpr_param _Tp, __constexpr_param _Rp> |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator<<=(this _Tp, _Rp) noexcept |
| // TODO: Remove `auto` when all support versions of Clang have https://llvm.org/PR202693 fixed. |
| -> constant_wrapper<auto(_Tp::value <<= _Rp::value)> { |
| return {}; |
| } |
| template <__constexpr_param _Tp, __constexpr_param _Rp> |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator>>=(this _Tp, _Rp) noexcept |
| // TODO: Remove `auto` when all support versions of Clang have https://llvm.org/PR202693 fixed. |
| -> constant_wrapper<auto(_Tp::value >>= _Rp::value)> { |
| return {}; |
| } |
| }; |
| |
| template <const auto& _Callable, class... _Args> |
| concept __constexpr_callable = (__constexpr_param<remove_cvref_t<_Args>> && ...) && requires { |
| typename constant_wrapper<std::invoke(_Callable, remove_cvref_t<_Args>::value...)>; |
| }; |
| |
| template <const auto& _Obj, class... _Args> |
| concept __constexpr_indexable = (__constexpr_param<remove_cvref_t<_Args>> && ...) && requires { |
| typename constant_wrapper<auto(_Obj[remove_cvref_t<_Args>::value...])>; |
| }; |
| |
| template <auto _Xp, class _Tp> |
| struct constant_wrapper : __cw_operators { |
| static constexpr decltype((_Xp)) value = (_Xp); |
| |
| using type = constant_wrapper; |
| using value_type = decltype(_Xp); |
| |
| static_assert(is_same_v<_Tp, value_type>, |
| "the second template parameter of std::constant_wrapper must be its value_type"); |
| |
| template <__constexpr_param _Rp> |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator=(_Rp) const noexcept |
| // TODO: Remove `auto` when all support versions of Clang have https://llvm.org/PR202693 fixed. |
| -> constant_wrapper<auto(value = _Rp::value)> { |
| return {}; |
| } |
| |
| _LIBCPP_HIDE_FROM_ABI constexpr operator decltype(value)() const noexcept { return value; } |
| |
| template <class... _Args> |
| requires __constexpr_callable<value, _Args...> |
| [[nodiscard]] |
| _LIBCPP_HIDE_FROM_ABI static constexpr constant_wrapper<std::invoke(value, remove_cvref_t<_Args>::value...)> |
| operator()(_Args&&...) noexcept { |
| return {}; |
| } |
| |
| template <class... _Args> |
| requires(!__constexpr_callable<value, _Args...> && is_invocable_v<const value_type&, _Args && ...>) |
| _LIBCPP_HIDE_FROM_ABI static constexpr decltype(auto) |
| operator()(_Args&&... __args) noexcept(noexcept(std::invoke(value, std::forward<_Args>(__args)...))) { |
| return std::invoke(value, std::forward<_Args>(__args)...); |
| } |
| |
| template <class... _Args> |
| requires __constexpr_indexable<value, _Args...> |
| [[nodiscard]] |
| _LIBCPP_HIDE_FROM_ABI static constexpr constant_wrapper<auto(value[remove_cvref_t<_Args>::value...])> |
| operator[](_Args&&...) noexcept { |
| return {}; |
| } |
| |
| template <class... _Args> |
| requires(!__constexpr_indexable<value, _Args...> && requires { value[std::declval<_Args>()...]; }) |
| _LIBCPP_HIDE_FROM_ABI static constexpr decltype(auto) |
| operator[](_Args&&... __args) noexcept(noexcept(value[std::forward<_Args>(__args)...])) { |
| return value[std::forward<_Args>(__args)...]; |
| } |
| }; |
| |
| #endif // _LIBCPP_STD_VER >= 26 |
| |
| _LIBCPP_END_NAMESPACE_STD |
| |
| #endif // _LIBCPP___UTILITY_CONSTANT_WRAPPER_H |
