singleton.hpp

/*
 Copyright (c) 2026 ETIB Corporation
 
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 */
 
#pragma once
 
#include <concepts>
 
namespace utility
{
 
    template<typename Type>
    concept CanBeSingleton =
        std::default_initializable<Type> && std::destructible<Type>;
 
    template<CanBeSingleton Type> class Singleton
    {
        public:
        // Delete copy constructor and assignment operator to prevent copying
        Singleton(const Singleton &)            = delete;
        Singleton &operator=(const Singleton &) = delete;
 
        static Type &getInstance(void)
        {
            static Singleton<Type> singleton;
            return singleton._instance;
        }
 
        private:
        // Private constructor to prevent direct instantiation
        Singleton(void) = default;
 
        Type _instance;    
    };
 
    template<typename Type>
    concept IsSingletonOf = requires {
        { Type::getInstance() } -> std::same_as<Type &>;
    };
 
}    // namespace utility