| //===----------------------------------------------------------------------===// |
| // |
| // 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/is_constructible.h> |
| #include <__type_traits/remove_cvref.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 <class _Tp> |
| struct __cw_fixed_value { |
| using __type _LIBCPP_NODEBUG = _Tp; |
| _LIBCPP_HIDE_FROM_ABI constexpr __cw_fixed_value(__type __v) noexcept : __data(__v) {} |
| _Tp __data; |
| }; |
| |
| template <class _Tp, size_t _Extent> |
| struct __cw_fixed_value<_Tp[_Extent]> { |
| using __type _LIBCPP_NODEBUG = _Tp[_Extent]; |
| _Tp __data[_Extent]; |
| |
| _LIBCPP_HIDE_FROM_ABI constexpr __cw_fixed_value(_Tp (&__arr)[_Extent]) noexcept |
| : __cw_fixed_value(__arr, make_index_sequence<_Extent>{}) {} |
| |
| private: |
| template <size_t... _Idxs> |
| _LIBCPP_HIDE_FROM_ABI constexpr __cw_fixed_value(_Tp (&__arr)[_Extent], index_sequence<_Idxs...>) noexcept |
| : __data{__arr[_Idxs]...} {} |
| }; |
| |
| template <class _Tp, size_t _Extent> |
| __cw_fixed_value(_Tp (&)[_Extent]) -> __cw_fixed_value<_Tp[_Extent]>; |
| |
| template <__cw_fixed_value _Xp, |
| # ifdef _LIBCPP_COMPILER_GCC |
| // gcc bug: https://gcc.gnu.org/PR117392 |
| class = typename decltype(__cw_fixed_value(_Xp))::__type |
| # else |
| class = typename decltype(_Xp)::__type |
| # endif |
| > |
| struct constant_wrapper; |
| |
| template <class _Tp> |
| concept __constexpr_param = requires { typename constant_wrapper<_Tp::value>; }; |
| |
| template <__cw_fixed_value _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 |
| -> constant_wrapper<(_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 |
| -> constant_wrapper<(_Tp::value += _Rp::value)> { |
| return {}; |
| } |
| template <__constexpr_param _Tp, __constexpr_param _Rp> |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator-=(this _Tp, _Rp) noexcept |
| -> constant_wrapper<(_Tp::value -= _Rp::value)> { |
| return {}; |
| } |
| template <__constexpr_param _Tp, __constexpr_param _Rp> |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator*=(this _Tp, _Rp) noexcept |
| -> constant_wrapper<(_Tp::value *= _Rp::value)> { |
| return {}; |
| } |
| template <__constexpr_param _Tp, __constexpr_param _Rp> |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator/=(this _Tp, _Rp) noexcept |
| -> constant_wrapper<(_Tp::value /= _Rp::value)> { |
| return {}; |
| } |
| template <__constexpr_param _Tp, __constexpr_param _Rp> |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator%=(this _Tp, _Rp) noexcept |
| -> constant_wrapper<(_Tp::value %= _Rp::value)> { |
| return {}; |
| } |
| template <__constexpr_param _Tp, __constexpr_param _Rp> |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator&=(this _Tp, _Rp) noexcept |
| -> constant_wrapper<(_Tp::value &= _Rp::value)> { |
| return {}; |
| } |
| template <__constexpr_param _Tp, __constexpr_param _Rp> |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator|=(this _Tp, _Rp) noexcept |
| -> constant_wrapper<(_Tp::value |= _Rp::value)> { |
| return {}; |
| } |
| template <__constexpr_param _Tp, __constexpr_param _Rp> |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator^=(this _Tp, _Rp) noexcept |
| -> constant_wrapper<(_Tp::value ^= _Rp::value)> { |
| return {}; |
| } |
| template <__constexpr_param _Tp, __constexpr_param _Rp> |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator<<=(this _Tp, _Rp) noexcept |
| -> constant_wrapper<(_Tp::value <<= _Rp::value)> { |
| return {}; |
| } |
| template <__constexpr_param _Tp, __constexpr_param _Rp> |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator>>=(this _Tp, _Rp) noexcept |
| -> constant_wrapper<(_Tp::value >>= _Rp::value)> { |
| return {}; |
| } |
| }; |
| |
| template <__cw_fixed_value _Xp, class> |
| struct constant_wrapper : __cw_operators { |
| static constexpr const auto& value = _Xp.__data; |
| using type = constant_wrapper; |
| using value_type = decltype(_Xp)::__type; |
| |
| private: |
| template <class... _Args> |
| requires(__constexpr_param<remove_cvref_t<_Args>> && ...) |
| _LIBCPP_HIDE_FROM_ABI static constexpr auto __call(_Args&&...) noexcept |
| -> constant_wrapper<std::invoke(value, remove_cvref_t<_Args>::value...)> { |
| return {}; |
| } |
| |
| template <class... _Args> |
| _LIBCPP_HIDE_FROM_ABI static constexpr auto |
| __call(_Args&&... __args) noexcept(noexcept(std::invoke(value, std::forward<_Args>(__args)...))) |
| -> decltype(std::invoke(value, std::forward<_Args>(__args)...)) { |
| return std::invoke(value, std::forward<_Args>(__args)...); |
| } |
| |
| template <class... _Args> |
| requires(__constexpr_param<remove_cvref_t<_Args>> && ...) |
| _LIBCPP_HIDE_FROM_ABI static constexpr auto __subscript(_Args&&...) noexcept |
| -> constant_wrapper<value[remove_cvref_t<_Args>::value...]> { |
| return {}; |
| } |
| |
| template <class... _Args> |
| _LIBCPP_HIDE_FROM_ABI static constexpr auto |
| __subscript(_Args&&... __args) noexcept(noexcept(value[std::forward<_Args>(__args)...])) |
| -> decltype(value[std::forward<_Args>(__args)...]) { |
| return value[std::forward<_Args>(__args)...]; |
| } |
| |
| public: |
| template <__constexpr_param _Rp> |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator=(_Rp) const noexcept |
| -> constant_wrapper<(value = _Rp::value)> { |
| return {}; |
| } |
| |
| _LIBCPP_HIDE_FROM_ABI constexpr operator decltype(value)() const noexcept { return value; } |
| |
| template <class... _Args> |
| _LIBCPP_HIDE_FROM_ABI static constexpr auto |
| operator()(_Args&&... __args) noexcept(noexcept(constant_wrapper::__call(std::forward<_Args>(__args)...))) |
| -> decltype(constant_wrapper::__call(std::forward<_Args>(__args)...)) { |
| return __call(std::forward<_Args>(__args)...); |
| } |
| |
| template <class... _Args> |
| _LIBCPP_HIDE_FROM_ABI static constexpr auto |
| operator[](_Args&&... __args) noexcept(noexcept(constant_wrapper::__subscript(std::forward<_Args>(__args)...))) |
| -> decltype(constant_wrapper::__subscript(std::forward<_Args>(__args)...)) { |
| return __subscript(std::forward<_Args>(__args)...); |
| } |
| }; |
| |
| #endif // _LIBCPP_STD_VER >= 26 |
| |
| _LIBCPP_END_NAMESPACE_STD |
| |
| #endif // _LIBCPP___UTILITY_CONSTANT_WRAPPER_H |
