mirror/magic_enum
1
0
Fork 0
mirror of https://github.com/Neargye/magic_enum.git synced 2026-01-09 23:34:23 +00:00
Code Activity

add suport enum_switch without defined MAGIC_ENUM_ENABLE_HASH

Browse source
This commit is contained in:
neargye 2022-11-08 20:21:00 +04:00
parent c588771875
commit 612033ab5d
2 changed files with 56 additions and 2 deletions
Download patch file Download diff file Expand all files Collapse all files

1
include/magic_enum.hpp
View file

@ -732,6 +732,7 @@ template <typename T>
struct underlying_type<T, true> : std::underlying_type<std::decay_t<T>> {};
#if defined(MAGIC_ENUM_ENABLE_HASH)
template <typename T>
inline constexpr bool has_hash = true;

57
include/magic_enum_switch.hpp
View file

@ -93,6 +93,53 @@ constexpr auto result_type() noexcept {
template <typename T, typename Result, typename F, typename D = std::decay_t<T>, typename R = typename decltype(result_type<D, Result, F>())::type>
using result_t = std::enable_if_t<std::is_enum_v<D> && !std::is_same_v<R, nonesuch>, R>;
#if !defined(MAGIC_ENUM_ENABLE_HASH)
template <typename T = void>
inline constexpr auto default_result_type_lambda = []() noexcept(std::is_nothrow_default_constructible_v<T>) { return T{}; };
template <>
inline constexpr auto default_result_type_lambda<void> = []() noexcept {};
template <typename R, typename F, typename... Args>
constexpr R invoke_r(F&& f, Args&&... args) noexcept(std::is_nothrow_invocable_r_v<R, F, Args...>) {
if constexpr (std::is_void_v<R>) {
std::forward<F>(f)(std::forward<Args>(args)...);
} else {
return static_cast<R>(std::forward<F>(f)(std::forward<Args>(args)...));
}
}
template <std::size_t I, std::size_t End, typename R, typename E, typename F, typename Def>
constexpr decltype(auto) constexpr_switch_impl(F&& f, E value, Def&& def) {
if constexpr(I < End) {
constexpr auto v = enum_constant<enum_value<E, I>()>{};
if (value == v) {
if constexpr (std::is_invocable_r_v<R, F, decltype(v)>) {
return invoke_r<R>(std::forward<F>(f), v);
} else {
return def();
}
} else {
return constexpr_switch_impl<I + 1, End, R>(std::forward<F>(f), value, std::forward<Def>(def));
}
} else {
return def();
}
}
template <typename R, typename E, typename F, typename Def>
constexpr decltype(auto) constexpr_switch(F&& f, E value, Def&& def) {
static_assert(is_enum_v<E>, "magic_enum::detail::constexpr_switch_impl requires enum type.");
if constexpr (count_v<E> == 0) {
return def();
} else {
return constexpr_switch_impl<0, count_v<E>, R>(std::forward<F>(f), value, std::forward<Def>(def));
}
}
#endif
} // namespace magic_enum::detail
template <typename Result = detail::default_result_type, typename E, typename F, typename R = detail::result_t<E, Result, F>>
@ -106,7 +153,10 @@ constexpr decltype(auto) enum_switch(F&& f, E value) {
value,
detail::default_result_type_lambda<R>);
#else
static_assert(detail::has_hash<D>, "magic_enum::enum_switch requires defined MAGIC_ENUM_ENABLE_HASH");
return detail::constexpr_switch<R, D>(
std::forward<F>(f),
value,
detail::default_result_type_lambda<R>);
#endif
}
@ -121,7 +171,10 @@ constexpr decltype(auto) enum_switch(F&& f, E value, Result&& result) {
value,
[&result]() -> R { return std::forward<Result>(result); });
#else
static_assert(detail::has_hash<D>, "magic_enum::enum_switch requires defined MAGIC_ENUM_ENABLE_HASH");
return detail::constexpr_switch<R, D>(
std::forward<F>(f),
value,
[&result]() -> R { return std::forward<Result>(result); });
#endif
}