介绍一个类型安全的回调库:libsigc++

#include <iostream>
#include <sigc++/sigc++.h>

class Cat
{
public:
void cry(int i){ std::cout << "cat:" << i << std::endl; }
};

class Dog
{
public:
void say(int i){ std::cout <<"dog:"<< i << std::endl; }
};

int main()
{
Cat cat3;
sigc::signal<void, int>mySignal3;
mySignal3.connect(sigc::mem_fun(cat3, &Cat::cry));
mySignal3.connect(sigc::mem_fun(Dog(), &Dog::say));
mySignal3.emit(001);  //向dog和cat发送信号。

return 0;
}

#include <iostream>
#include <string>

#include <sigc++/sigc++.h>

void speak(const std::string& str)
{
std::cout << str;
}

int main()
{
sigc::signal<void, const std::string&> mySignal;

mySignal.connect(sigc::ptr_fun(&speak));

mySignal.emit("hello world\n");

return 0;
}