C++11写一个只触发一次槽函数的Qtconnect函数

#pragma once
#include <QObject>
#include <QMap>
namespace ConnectionUtil
{
    typedef QMetaObject::Connection Conn;
    struct ConnKey {};
    extern QMap<ConnKey*, QPair<Conn, Conn>> connMap;
    class ReceiverObj : public QObject
    {
        Q_OBJECT
    public:
        explicit ReceiverObj(ConnKey *connKey) : key(connKey) {}
    public slots:
        void slot();
    private:
        ConnKey *key;
    };
    // 处理信号为SIGNAL(...)的情况
    template <typename Sender, typename ...Args>
    void connect(Sender &&sender, const char *signal, Args &&...args)
    {
        ConnKey *connKey = new ConnKey;
        Conn conn1 = QObject::connect(std::forward<Sender>(sender), signal, std::forward<Args>(args)...);
        Conn conn2 = QObject::connect(std::forward<Sender>(sender), signal, new ReceiverObj(connKey), SLOT(slot()));
        connMap.insert(connKey, qMakePair(std::move(conn1), std::move(conn2)));
    }
    // 处理其他情况
    template <typename Sender, typename Signal, typename ...Args>
    void connect(Sender &&sender, Signal &&signal, Args &&...args)
    {
        ConnKey *connKey = new ConnKey;
        Conn conn1 = QObject::connect(std::forward<Sender>(sender), std::forward<Signal>(signal), std::forward<Args>(args)...);
        Conn conn2 = QObject::connect(std::forward<Sender>(sender), std::forward<Signal>(signal), [connKey] { ReceiverObj(connKey).slot(); });
        connMap.insert(connKey, qMakePair(std::move(conn1), std::move(conn2)));
    }
}

#include "ConnectionUtil.h"
using namespace ConnectionUtil;
QMap<ConnKey *, QPair<Conn, Conn>> ConnectionUtil::connMap;
void ReceiverObj::slot()
{
    const QPair<Conn, Conn> &connections = connMap.value(key);
    QObject::disconnect(connections.first);
    QObject::disconnect(connections.second);
    connMap.remove(key);
    delete key;
    deleteLater();
}

ConnectionUtil::connect(this, SIGNAL(bong(int)), obj, SLOT(slotBong(int)), Qt::QueuedConnection);
ConnectionUtil::connect(this, &MainWindow::bong, obj, &SomeObject::slotBong, Qt::QueuedConnection);
ConnectionUtil::connect(this, &MainWindow::bong, this, []() {
    qDebug() << "binGo";
});