C++ 模板类 模板成员函数

  最近看了C++ 的sigslot库，对其里面模板类 模板成员函数的一些用法记录下

#include <iostream>
#include "sigslot.h"

using namespace sigslot;

class Switch
{
public:
	signal0<>  clicked;
};

class Light : public has_slots<>
{
public:
	void on()
	{
		std::cout << "the light is on\n";
	}
};


int main(int argc, char *argv[])
{
	Light light;
	Switch sw;
	sw.clicked.connect(&light, &Light::on);

	sw.clicked.emit();


	system("pause");

	return 0;
}

其中signal0<>  clicked为模板类，sw.clicked.connect为模板类模板成员函数，看下它的实现：

template<class mt_policy = SIGSLOT_DEFAULT_MT_POLICY>
	class signal0 : public _signal_base0<mt_policy>
	{
	public:
		typedef _signal_base0<mt_policy> base;
		typedef typename base::connections_list connections_list;
		using base::m_connected_slots;

		signal0()
		{
			;
		}

		signal0(const signal0<mt_policy>& s)
			: _signal_base0<mt_policy>(s)
		{
			;
		}

		template<class desttype>
		void connect(desttype* pclass, void (desttype::* pmemfun)())
		{
			lock_block<mt_policy> lock(this);
			_connection0<desttype, mt_policy>* conn =
				new _connection0<desttype, mt_policy>(pclass, pmemfun);
			m_connected_slots.push_back(conn);
			pclass->signal_connect(this);
		}

		void emit()
		{
			lock_block<mt_policy> lock(this);
			typename connections_list::const_iterator itNext, it = m_connected_slots.begin();
			typename connections_list::const_iterator itEnd = m_connected_slots.end();

			while (it != itEnd)
			{
				itNext = it;
				++itNext;

				(*it)->emit();

				it = itNext;
			}
		}

		void operator()()
		{
			lock_block<mt_policy> lock(this);
			typename connections_list::const_iterator itNext, it = m_connected_slots.begin();
			typename connections_list::const_iterator itEnd = m_connected_slots.end();

			while (it != itEnd)
			{
				itNext = it;
				++itNext;

				(*it)->emit();

				it = itNext;
			}
		}
	};

其中template<class desttype>

void connect(desttype* pclass, void (desttype::* pmemfun)()) 为类模板模板成员函数的写法，sw.clicked.connect(&light, &Light::on);为模板成员函数的调用。