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- #ifndef NEARGYE_MAGIC_ENUM_FUSE_HPP
- #define NEARGYE_MAGIC_ENUM_FUSE_HPP
- #include "magic_enum.hpp"
- namespace magic_enum {
- namespace detail {
- template <typename E>
- constexpr optional<std::uintmax_t> fuse_one_enum(optional<std::uintmax_t> hash, E value) noexcept {
- if (hash) {
- if (const auto index = enum_index(value)) {
- return (*hash << log2(enum_count<E>() + 1)) | *index;
- }
- }
- return {};
- }
- template <typename E>
- constexpr optional<std::uintmax_t> fuse_enum(E value) noexcept {
- return fuse_one_enum(0, value);
- }
- template <typename E, typename... Es>
- constexpr optional<std::uintmax_t> fuse_enum(E head, Es... tail) noexcept {
- return fuse_one_enum(fuse_enum(tail...), head);
- }
- template <typename... Es>
- constexpr auto typesafe_fuse_enum(Es... values) noexcept {
- enum class enum_fuse_t : std::uintmax_t;
- const auto fuse = fuse_enum(values...);
- if (fuse) {
- return optional<enum_fuse_t>{static_cast<enum_fuse_t>(*fuse)};
- }
- return optional<enum_fuse_t>{};
- }
- }
- template <typename... Es>
- [[nodiscard]] constexpr auto enum_fuse(Es... values) noexcept {
- static_assert((std::is_enum_v<std::decay_t<Es>> && ...), "magic_enum::enum_fuse requires enum type.");
- static_assert(sizeof...(Es) >= 2, "magic_enum::enum_fuse requires at least 2 values.");
- static_assert((detail::log2(enum_count<std::decay_t<Es>>() + 1) + ...) <= (sizeof(std::uintmax_t) * 8), "magic_enum::enum_fuse does not work for large enums");
- #if defined(MAGIC_ENUM_NO_TYPESAFE_ENUM_FUSE)
- const auto fuse = detail::fuse_enum<std::decay_t<Es>...>(values...);
- #else
- const auto fuse = detail::typesafe_fuse_enum<std::decay_t<Es>...>(values...);
- #endif
- return assert(fuse), fuse;
- }
- }
- #endif
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