KSG-Framework/Maybe.h

#pragma once

#include <functional>
#include "Betriebssystem.h"

namespace Frmaework
{
    template<typename T>
    class Maybe
    {
    private:
        bool set;
        T value;

        Maybe() 
        { 
            set = 0;
        }

    public:
        static Maybe<T> of( T value )
        {
            return { 1, value };
        }

        static Maybe<T> empty()
        {
            return { 0, value };
        }

        bool isEmpty() const
        {
            return !set;
        }

        bool isPresent() const
        {
            return set;
        }

        operator T() const
        {
            assert( set );
            return value;
        }

        void ifPresent( std::function<T> action )
        {
            if( set )
                action( value );
        }

        void ifNotPresent( std::function<T> action )
        {
            if( !set )
                action( value );
        }

        T operator->()
        {
            assert( set );
            return current->var;
        }
    };
}