UUIDGenerator.hpp

// SPDX-FileCopyrightText: 2025 Vincent Leroy
// SPDX-License-Identifier: MIT
//
// This file is part of dfx.
//
// Licensed under the MIT License. See the LICENSE file in the project root
// for full license information.
 
#pragma once
 
// Standard includes
#include <array>
#include <cstdint>
#include <string>
#include <random>
 
namespace dfx::Utils
{
struct UUID : public std::array<uint8_t, 16>
{
    UUID();

    bool isValid() const noexcept;
    std::string toString() const;
};

class UUIDGenerator
{
public:
    static UUID generate();
 
private:
    UUIDGenerator();
 
private:
    std::mt19937                           _gen;
    std::uniform_int_distribution<uint8_t> _dist;
};
} // !namespace dfx::Utils
 
namespace std
{
template<>
struct hash<dfx::Utils::UUID>
{
    std::size_t operator()(dfx::Utils::UUID const & uuid) const noexcept
    {
        // Combine bytes into size_t using a common hash combining strategy
        std::size_t hash = 0;
        for (auto const byte : uuid)
            hash ^= static_cast<std::size_t>(byte) + 0x9e3779b9 + (hash << 6) + (hash >> 2);
        return hash;
    }
};
} // !namespace std