Kylin/Universal/Private/PromiseResolver.h

#ifndef __PROMISERESOLVER_H__
#define __PROMISERESOLVER_H__

#include "PromiseException.h"

template <typename T>
class Promise;

template <typename T>
class PromiseResolver {
public:
    PromiseResolver(Promise<T> promise) : m_d{promise.m_d} {
    }

    template <typename V>
    void resolve(V &&value) {
        if (m_d) {
            assert(m_d->isPending());
            m_d->resolve(std::forward<V>(value));
            m_d->dispatch();
        }
    }

    void resolve() {
        if (m_d) {
            assert(m_d->isPending());
            m_d->resolve();
            m_d->dispatch();
        }
    }

    template <typename E>
    void reject(E &&error) {
        if (m_d) {
            assert(m_d->isPending());
            m_d->reject(std::forward<E>(error));
            m_d->dispatch();
        }
    }

    void reject() {
        if (m_d) {
            assert(m_d->isPending());
            m_d->reject(PromiseUndefinedException{});
            m_d->dispatch();
        }
    }

private:
    std::shared_ptr<PromiseData<T>> m_d;
};

template <typename T>
class PromiseResolve {
public:
    PromiseResolve(PromiseResolver<T> resolver) : m_resolver{std::move(resolver)} {
    }

    template <typename V>
    void operator()(V &&value) const {
        m_resolver.resolve(std::forward<V>(value));
    }

    void operator()() const {
        m_resolver.resolve();
    }

private:
    mutable PromiseResolver<T> m_resolver;
};

template <typename T>
class PromiseReject {
public:
    PromiseReject(PromiseResolver<T> resolver) : m_resolver{std::move(resolver)} {
    }

    template <typename E>
    void operator()(E &&error) const {
        m_resolver.reject(std::forward<E>(error));
    }

    void operator()() const {
        m_resolver.reject();
    }

private:
    mutable PromiseResolver<T> m_resolver;
};

#endif // __PROMISERESOLVER_H__