awaitable.h

#pragma once
 
namespace resumef
{
 
    template<class _Ty>
    struct awaitable_impl_t
    {
        using value_type = _Ty;
        using state_type = state_t<value_type>;
        using future_type = future_t<value_type>;
        using lock_type = typename state_type::lock_type;
        using _Alloc_char = typename state_type::_Alloc_char;
 
        awaitable_impl_t() {}
        awaitable_impl_t(const awaitable_impl_t&) = default;
        awaitable_impl_t(awaitable_impl_t&&) = default;
 
        awaitable_impl_t& operator = (const awaitable_impl_t&) = default;
        awaitable_impl_t& operator = (awaitable_impl_t&&) = default;
 
        void set_exception(std::exception_ptr e) const
        {
            this->_state->set_exception(std::move(e));
            this->_state = nullptr;
        }
 
        template<class _Exp>
        void throw_exception(_Exp e) const
        {
            set_exception(std::make_exception_ptr(std::move(e)));
        }
 
        future_type get_future() noexcept
        {
            return future_type{ this->_state };
        }
 
        mutable counted_ptr<state_type> _state = state_future_t::_Alloc_state<state_type>(true);
    };
 
    template<class _Ty>
    struct [[nodiscard]] awaitable_t : public awaitable_impl_t<_Ty>
    {
        using typename awaitable_impl_t<_Ty>::value_type;
        using awaitable_impl_t<_Ty>::awaitable_impl_t;
 
        template<class U>
        void set_value(U&& value) const
        {
            this->_state->set_value(std::forward<U>(value));
            this->_state = nullptr;
        }
    };
 
#ifndef DOXYGEN_SKIP_PROPERTY
    template<class _Ty>
    struct [[nodiscard]] awaitable_t<_Ty&> : public awaitable_impl_t<_Ty&>
    {
        using typename awaitable_impl_t<_Ty&>::value_type;
        using awaitable_impl_t<_Ty&>::awaitable_impl_t;
 
        void set_value(_Ty& value) const
        {
            this->_state->set_value(value);
            this->_state = nullptr;
        }
    };
 
    template<>
    struct [[nodiscard]] awaitable_t<void> : public awaitable_impl_t<void>
    {
        using awaitable_impl_t<void>::awaitable_impl_t;
 
        void set_value() const
        {
            this->_state->set_value();
            this->_state = nullptr;
        }
    };
#endif  //DOXYGEN_SKIP_PROPERTY
}