SmartEnum.h

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/*
 * This file is part of the TrinityCore Project. See AUTHORS file for Copyright information
 *
 * This program 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; either version 2 of the License, or (at your
 * option) any later version.
 *
 * This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
 */
 
#ifndef TRINITY_SMARTENUM_H
#define TRINITY_SMARTENUM_H
 
#include "Define.h"
#include "IteratorPair.h"
#include <iterator>
 
struct EnumText
{
    EnumText(char const* c, char const* t, char const* d) : Constant(c), Title(t), Description(d) { }
    // Enum constant of the value
    char const* const Constant;
    // Human-readable title of the value
    char const* const Title;
    // Human-readable description of the value
    char const* const Description;
};
 
namespace Trinity::Impl::EnumUtilsImpl
{
    template <typename Enum>
    struct EnumUtils
    {
        static size_t Count();
        static EnumText ToString(Enum value);
        static Enum FromIndex(size_t index);
        static size_t ToIndex(Enum index);
    };
}
 
class EnumUtils
{
    public:
        template <typename Enum>
        static size_t Count() { return Trinity::Impl::EnumUtilsImpl::EnumUtils<Enum>::Count(); }
        template <typename Enum>
        static EnumText ToString(Enum value) { return Trinity::Impl::EnumUtilsImpl::EnumUtils<Enum>::ToString(value); }
        template <typename Enum>
        static Enum FromIndex(size_t index) { return Trinity::Impl::EnumUtilsImpl::EnumUtils<Enum>::FromIndex(index); }
        template <typename Enum>
        static uint32 ToIndex(Enum value) { return Trinity::Impl::EnumUtilsImpl::EnumUtils<Enum>::ToIndex(value);}
 
        template<typename Enum>
        static bool IsValid(Enum value)
        {
            try
            {
                Trinity::Impl::EnumUtilsImpl::EnumUtils<Enum>::ToIndex(value);
                return true;
            } catch (...)
            {
                return false;
            }
        }
 
        template<typename Enum>
        static bool IsValid(std::underlying_type_t<Enum> value) { return IsValid(static_cast<Enum>(value)); }
 
        template <typename Enum>
        class Iterator
        {
            public:
                using iterator_category = std::random_access_iterator_tag;
                using value_type = Enum;
                using pointer = Enum*;
                using reference = Enum&;
                using difference_type = std::ptrdiff_t;
 
                Iterator() : _index(EnumUtils::Count<Enum>()) {}
                explicit Iterator(size_t index) : _index(index) { }
 
                bool operator==(const Iterator& other) const = default;
                std::strong_ordering operator<=>(const Iterator& other) const = default;
 
                difference_type operator-(Iterator const& other) const { return _index - other._index; }
 
                value_type operator[](difference_type d) const { return FromIndex<Enum>(_index + d); }
                value_type operator*() const { return operator[](0); }
 
                Iterator& operator+=(difference_type d) { _index += d; return *this; }
                Iterator& operator++() { return operator+=(1); }
                Iterator operator++(int) { Iterator i = *this; operator++(); return i; }
                Iterator operator+(difference_type d) const { Iterator i = *this; i += d; return i; }
 
                Iterator& operator-=(difference_type d) { _index -= d; return *this; }
                Iterator& operator--() { return operator-=(1); }
                Iterator operator--(int) { Iterator i = *this; operator--(); return i; }
                Iterator operator-(difference_type d) const { Iterator i = *this; i -= d; return i; }
 
            private:
                difference_type _index;
        };
 
        template <typename Enum>
        static Iterator<Enum> Begin() { return Iterator<Enum>(0); }
 
        template <typename Enum>
        static Iterator<Enum> End() { return Iterator<Enum>(); }
 
        template <typename Enum>
        static Trinity::IteratorPair<Iterator<Enum>> Iterate() { return { Begin<Enum>(), End<Enum>() }; }
 
        template <typename Enum>
        static char const* ToConstant(Enum value) { return ToString(value).Constant; }
 
        template <typename Enum>
        static char const* ToTitle(Enum value) { return ToString(value).Title; }
 
        template <typename Enum>
        static char const* ToDescription(Enum value) { return ToString(value).Description; }
};
 
#endif