subscription_base.hpp

//                  ReactivePlusPlus library
//
//          Copyright Aleksey Loginov 2022 - present.
// Distributed under the Boost Software License, Version 1.0.
//    (See accompanying file LICENSE_1_0.txt or copy at
//          https://www.boost.org/LICENSE_1_0.txt)
//
// Project home: https://github.com/victimsnino/ReactivePlusPlus
//
 
#pragma once
 
#include <rpp/subscriptions/details/subscription_state.hpp>
 
#include <memory>
 
namespace rpp
{
class composite_subscription;
 
class subscription_base
{
protected:
    subscription_base(std::shared_ptr<details::subscription_state> state)
        : m_state{std::move(state)} {}
 
    const std::shared_ptr<details::subscription_state>& get_state() const { return m_state; }
 
    friend rpp::composite_subscription;
public:
    subscription_base()
        : m_state{std::make_shared<details::subscription_state>()} {}
 
    subscription_base(const subscription_base&)                      = default;
    subscription_base(subscription_base&&) noexcept                  = default;
    subscription_base& operator=(const subscription_base& other)     = default;
    subscription_base& operator=(subscription_base&& other) noexcept = default;
 
    bool operator==(const subscription_base& rhs) const = default;
 
    virtual ~subscription_base() = default;
 
    static subscription_base empty() { return subscription_base{ nullptr }; }
 
    [[nodiscard]] bool is_subscribed() const
    {
        return m_state && m_state->is_subscribed();
    }
 
    void unsubscribe() const
    {
        if (m_state)
        {
            m_state->unsubscribe();
            m_state.reset();
        }
    }
 
private:
    mutable std::shared_ptr<details::subscription_state> m_state{};
};
 
} // namespace rpp