automaton_transition_label.h

#ifndef PASTELSYS_AUTOMATON_TRANSITION_LABEL_H
#define PASTELSYS_AUTOMATON_TRANSITION_LABEL_H

#include "pastel/sys/automaton/automaton_fwd.h"
#include "pastel/sys/optional/optional.h"

namespace Pastel
{

    template <
        typename Symbol, 
        typename StateData, 
        typename TransitionData>
    class Automaton_Fwd;

    namespace Automaton_
    {

        template <
            typename Symbol, 
            typename StateData, 
            typename TransitionData>
        class TransitionLabel
            : public Automaton_Fwd<Symbol, StateData, TransitionData>::TransitionData_Class
        {
        public:
            using Fwd = Automaton_Fwd<Symbol, StateData, TransitionData>;

            PASTEL_FWD(TransitionData_Class);

            // FIX: Delete after emplace becomes available in Visual Studio.
            TransitionLabel(TransitionLabel&& that)
                : TransitionData_Class(std::move((TransitionData_Class&&)that))
                , symbol_(std::move(that.symbol_))
            {
            }

            const Optional<Symbol>& symbol() const
            {
                return symbol_;
            }

            //! Assigns to the contained data.
            template <typename Type>
            TransitionLabel& operator=(Type&& that)
            {
                ((TransitionData_Class&)*this) = std::forward<Type>(that);
                return *this;
            }

        private:
            TransitionLabel() = delete;
            TransitionLabel(const TransitionLabel& that) = delete;
            TransitionLabel& operator=(const TransitionLabel& that) = delete;

        private:
            template <
                typename, typename, 
                typename, typename>
            friend class Pastel::Automaton;

            TransitionLabel(
                Optional<Symbol> symbol,
                TransitionData_Class transitionData)
                : TransitionData_Class(std::move(transitionData))
                , symbol_(std::move(symbol))
            {
            }

            Optional<Symbol> symbol_;
        };

    }

}

#endif