| Line | Branch | Exec | Source |
|---|---|---|---|
| 1 | //====================================================================================================================== | ||
| 2 | /* | ||
| 3 | KUMI - Compact Tuple Tools | ||
| 4 | Copyright : KUMI Project Contributors | ||
| 5 | SPDX-License-Identifier: BSL-1.0 | ||
| 6 | */ | ||
| 7 | //====================================================================================================================== | ||
| 8 | #pragma once | ||
| 9 | |||
| 10 | namespace kumi | ||
| 11 | { | ||
| 12 | //==================================================================================================================== | ||
| 13 | /** | ||
| 14 | @ingroup kumi_types | ||
| 15 | @class unit | ||
| 16 | @brief A type representing the product of no type, also called the unit type | ||
| 17 | |||
| 18 | kumi::unit provides a way to define the unit type in a constexpr friendly manner. | ||
| 19 | @see @ref kumi_unit | ||
| 20 | **/ | ||
| 21 | //==================================================================================================================== | ||
| 22 | struct unit | ||
| 23 | { | ||
| 24 | 6 | KUMI_ABI friend constexpr auto operator<=>(unit, unit) noexcept = default; | |
| 25 | |||
| 26 | template<typename T> | ||
| 27 | [[nodiscard]] KUMI_ABI constexpr operator T() const noexcept | ||
| 28 | requires(kumi::concepts::unit_type<T>) | ||
| 29 | { | ||
| 30 | return {}; | ||
| 31 | } | ||
| 32 | |||
| 33 | template<typename T> | ||
| 34 | [[nodiscard]] KUMI_ABI constexpr operator T() noexcept | ||
| 35 | requires(kumi::concepts::unit_type<T>) | ||
| 36 | { | ||
| 37 | return {}; | ||
| 38 | } | ||
| 39 | |||
| 40 | template<typename CharT, typename Traits> | ||
| 41 | 5 | friend std::basic_ostream<CharT, Traits>& operator<<(std::basic_ostream<CharT, Traits>& os, unit) noexcept | |
| 42 | { | ||
| 43 | 5 | return os << '\'' << "none" << '\''; | |
| 44 | } | ||
| 45 | }; | ||
| 46 | |||
| 47 | //==================================================================================================================== | ||
| 48 | /** | ||
| 49 | @ingroup kumi_utility | ||
| 50 | @brief Inline constant representing a kumi::unit. | ||
| 51 | **/ | ||
| 52 | //==================================================================================================================== | ||
| 53 | inline constexpr kumi::unit none{}; | ||
| 54 | } | ||
| 55 |