UUID.h

// Copyright(c) 2019 - 2020, #Momo
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#pragma once

#include <utility>
#include <ostream>
#include <istream>

#include "Utilities/STL/MxString.h"

namespace boost::uuids
{
    struct uuid;
    class random_generator_pure;
}

namespace MxEngine
{
    class UUID
    {
        std::aligned_storage_t<16> uuidImpl;

        friend class UUIDGenerator;
    public:
        boost::uuids::uuid& GetImpl();
        const boost::uuids::uuid& GetImpl() const;
        size_t GetHashCode() const;
        bool operator==(const UUID& other) const;
        bool operator< (const UUID& other) const;
        bool operator!=(const UUID& other) const;
        bool operator> (const UUID& other) const;
        bool operator<=(const UUID& other) const;
        bool operator>=(const UUID& other) const;

        operator MxString() const;
    };

    std::ostream& operator<<(std::ostream& out, const UUID& uuid);
    std::istream& operator>>(std::istream& in, UUID& uuid);

    struct UUIDGeneratorImpl
    {
        std::aligned_storage_t<8> generator;
        boost::uuids::random_generator_pure& GetGeneratorImpl();
    };

    class UUIDGenerator
    {
        static inline UUIDGeneratorImpl* storage;
    public:
        static void Init();
        static UUID Get();
        static UUID GetNull();
        static void Clone(UUIDGeneratorImpl* other);
        static UUIDGeneratorImpl* GetImpl();
    };
}

#define HASH_ALGORITHM(NAMESPACE)\
namespace NAMESPACE\
{\
    template<typename T> struct hash;\
    template <>\
    struct hash<MxEngine::UUID>\
    {\
        std::size_t operator()(const MxEngine::UUID& Id) const\
        {\
            return Id.GetHashCode();\
        }\
    };\
}

HASH_ALGORITHM(std)
HASH_ALGORITHM(eastl)
#undef HASH_ALGORITHM