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Codechange: use traits to add increment/decrement operators to enums when requested

pull/13397/head
Rubidium 2025-01-19 14:52:11 +01:00 committed by rubidium42
parent 4b2b113292
commit 0207f91b8d
1 changed files with 46 additions and 13 deletions
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59
src/core/enum_type.hpp
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@ -14,21 +14,54 @@
template <typename enum_type>
constexpr std::underlying_type_t<enum_type> to_underlying(enum_type e) { return static_cast<std::underlying_type_t<enum_type>>(e); }
/** Trait to enable prefix/postfix incrementing operators. */
template <typename enum_type>
struct is_enum_incrementable {
static constexpr bool value = false;
};
template <typename enum_type>
constexpr bool is_enum_incrementable_v = is_enum_incrementable<enum_type>::value;
/** Prefix increment. */
template <typename enum_type, std::enable_if_t<is_enum_incrementable_v<enum_type>, bool> = true>
inline constexpr enum_type &operator ++(enum_type &e)
{
e = static_cast<enum_type>(to_underlying(e) + 1);
return e;
}
/** Postfix increment, uses prefix increment. */
template <typename enum_type, std::enable_if_t<is_enum_incrementable_v<enum_type>, bool> = true>
inline constexpr enum_type operator ++(enum_type &e, int)
{
enum_type e_org = e;
++e;
return e_org;
}
/** Prefix decrement. */
template <typename enum_type, std::enable_if_t<is_enum_incrementable_v<enum_type>, bool> = true>
inline constexpr enum_type &operator --(enum_type &e)
{
e = static_cast<enum_type>(to_underlying(e) - 1);
return e;
}
/** Postfix decrement, uses prefix decrement. */
template <typename enum_type, std::enable_if_t<is_enum_incrementable_v<enum_type>, bool> = true>
inline constexpr enum_type operator --(enum_type &e, int)
{
enum_type e_org = e;
--e;
return e_org;
}
/** Some enums need to have allowed incrementing (i.e. StationClassID) */
#define DECLARE_POSTFIX_INCREMENT(enum_type) \
inline constexpr enum_type operator ++(enum_type& e, int) \
{ \
enum_type e_org = e; \
e = static_cast<enum_type>(to_underlying(e) + 1); \
return e_org; \
} \
inline constexpr enum_type operator --(enum_type& e, int) \
{ \
enum_type e_org = e; \
e = static_cast<enum_type>(to_underlying(e) - 1); \
return e_org; \
}
template <> struct is_enum_incrementable<enum_type> { \
static const bool value = true; \
};
/** Operators to allow to work with enum as with type safe bit set in C++ */