state.hpp

//Copyright Florian Goujeon 2021 - 2026.
//Distributed under the Boost Software License, Version 1.0.
//(See accompanying file LICENSE or copy at
//https://www.boost.org/LICENSE_1_0.txt)
//Official repository: https://github.com/fgoujeon/maki
 
#ifndef MAKI_REGION_STATE_HPP
#define MAKI_REGION_STATE_HPP
 
#include "detail/type_set.hpp"
#include "detail/pretty_name.hpp"
#include "detail/friendly_impl.hpp"
#include "detail/tlu/left_fold.hpp"
#include <string_view>
#include <utility>
 
namespace maki
{

template<class Impl>
class state
{
public:
#ifndef MAKI_DETAIL_DOXYGEN
    template<class... Args>
    constexpr state(Args&&... args):
        impl_(std::forward<Args>(args)...)
    {
    }
#endif
 
    state(const state&) = delete;
    state(state&&) = delete;
    state& operator=(const state&) = delete;
    state& operator=(state&&) = delete;
    ~state() = default;

    template<const auto& StateMold>
    [[nodiscard]] const auto& substate() const
    {
        return impl_.template state<StateMold>();
    }

    template<int Index>
    [[nodiscard]] const auto& region() const
    {
        return impl_.template region<Index>();
    }

    template<const auto& StateMold>
    [[nodiscard]] bool is() const
    {
        return impl_.template is<StateMold>();
    }

    [[nodiscard]] const auto& context() const
    {
        return impl_.context();
    }

    [[nodiscard]] static std::string_view pretty_name()
    {
        return detail::pretty_name<Impl::mold>();
    }
 
private:
    MAKI_DETAIL_FRIENDLY_IMPL
 
    using impl_type = Impl;
 
    impl_type impl_;
};
 
namespace detail
{
    template<class EventTypeSet, class State>
    using state_type_list_event_type_set_operation_t = type_set_union_t
    <
        EventTypeSet,
        typename impl_of_t<State>::event_type_set
    >;
 
    template<class StateTypeList>
    using state_type_list_event_type_set_t = tlu::left_fold_t
    <
        StateTypeList,
        state_type_list_event_type_set_operation_t,
        empty_type_set_t
    >;
}
 
} //namespace
 
#endif