enum_type.hpp

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/*
 * This file is part of OpenTTD.
 * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
 * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
 */
 
#ifndef ENUM_TYPE_HPP
#define ENUM_TYPE_HPP
 
#include "base_bitset_type.hpp"
 
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); }
 
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;
 
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;
}
 
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;
}
 
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;
}
 
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;
}
 
#define DECLARE_INCREMENT_DECREMENT_OPERATORS(enum_type) \
  template <> struct is_enum_incrementable<enum_type> { \
    static const bool value = true; \
  };
 
 
#define DECLARE_ENUM_AS_BIT_SET(enum_type) \
  inline constexpr enum_type operator | (enum_type m1, enum_type m2) { return static_cast<enum_type>(to_underlying(m1) | to_underlying(m2)); } \
  inline constexpr enum_type operator & (enum_type m1, enum_type m2) { return static_cast<enum_type>(to_underlying(m1) & to_underlying(m2)); } \
  inline constexpr enum_type operator ^ (enum_type m1, enum_type m2) { return static_cast<enum_type>(to_underlying(m1) ^ to_underlying(m2)); } \
  inline constexpr enum_type& operator |= (enum_type& m1, enum_type m2) { m1 = m1 | m2; return m1; } \
  inline constexpr enum_type& operator &= (enum_type& m1, enum_type m2) { m1 = m1 & m2; return m1; } \
  inline constexpr enum_type& operator ^= (enum_type& m1, enum_type m2) { m1 = m1 ^ m2; return m1; } \
  inline constexpr enum_type operator ~(enum_type m) { return static_cast<enum_type>(~to_underlying(m)); }
 
#define DECLARE_ENUM_AS_ADDABLE(EnumType) \
  template <typename OtherEnumType, typename = typename std::enable_if<std::is_enum_v<OtherEnumType>, OtherEnumType>::type> \
  constexpr OtherEnumType operator + (OtherEnumType m1, EnumType m2) { \
    return static_cast<OtherEnumType>(to_underlying(m1) + to_underlying(m2)); \
  }
 
template <typename T, class = typename std::enable_if_t<std::is_enum_v<T>>>
debug_inline constexpr bool HasFlag(const T x, const T y)
{
  return (x & y) == y;
}
 
template <typename T, class = typename std::enable_if_t<std::is_enum_v<T>>>
debug_inline constexpr void ToggleFlag(T &x, const T y)
{
  if (HasFlag(x, y)) {
    x &= ~y;
  } else {
    x |= y;
  }
}
 
template <typename Tstorage, typename Tenum, Tenum Tend_value>
struct EnumBitSetMask {
  static constexpr Tstorage value = std::numeric_limits<Tstorage>::max() >> (std::numeric_limits<Tstorage>::digits - to_underlying(Tend_value));
};
 
template <typename Tenum, typename Tstorage, Tenum Tend_value = Tenum{std::numeric_limits<Tstorage>::digits}>
class EnumBitSet : public BaseBitSet<EnumBitSet<Tenum, Tstorage, Tend_value>, Tenum, Tstorage, EnumBitSetMask<Tstorage, Tenum, Tend_value>::value> {
  using BaseClass = BaseBitSet<EnumBitSet<Tenum, Tstorage, Tend_value>, Tenum, Tstorage, EnumBitSetMask<Tstorage, Tenum, Tend_value>::value>;
public:
  using EnumType = BaseClass::ValueType;
 
  constexpr EnumBitSet() : BaseClass() {}
  constexpr EnumBitSet(Tenum value) : BaseClass() { this->Set(value); }
  explicit constexpr EnumBitSet(Tstorage data) : BaseClass(data) {}
 
  constexpr EnumBitSet(std::initializer_list<const Tenum> values) : BaseClass()
  {
    for (const Tenum &value : values) {
      this->Set(value);
    }
  }
 
  constexpr auto operator <=>(const EnumBitSet &) const noexcept = default;
 
  static constexpr size_t DecayValueType(const BaseClass::ValueType &value) { return to_underlying(value); }
};
 
#endif /* ENUM_TYPE_HPP */