量化交易之c++篇 - boost库 - 信号槽机制
    
#include <iostream>
#include <boost/signals2.hpp>
using namespace boost::signals2;
void slot1(int value) {
    std::cout << "slot1 received value: " << value << std::endl;
}
void slot2(int value1, int value2) {
    std::cout << "slot2 received values: " << value1 << " and " << value2 << std::endl;
}
int main() {
    using OneVarType = void(int);
    using TwoVarType = void(int, int);
    // 定义信号类型
    signal<OneVarType> sig1;
    signal<TwoVarType> sig2;
    // 连接信号和槽
    connection conn1 = sig1.connect(&slot1);
    connection conn2 = sig2.connect(&slot2);
    // 发射信号
    sig1(100);
    sig2(200, 300);
    // 断开连接
    conn1.disconnect();
    conn2.disconnect();
    return 0;
}
// 带返回值类型的信号槽
#include <iostream>
#include <boost/signals2.hpp>
using namespace boost::signals2;
int slots1(int a) {
    std::cout << "slot 1 called " << a << std::endl;
    return a + 1;
}
int slots2(int a) {
    std::cout << "slot 2 called " << a << std::endl;
    return a + 2;
}
int slots3(int a) {
    std::cout << "slot 3 called " << a << std::endl;
    return a + 3;
}
int main() {
    using signalType = int(int);
    signal<signalType> sig;
    sig.connect(&slots1);
    std::cout << *sig(0) << std::endl;
    sig.disconnect(&slots1);
    sig.connect(&slots2);
    std::cout << *sig(0) << std::endl;
    sig.disconnect(&slots2);
    sig.connect(&slots3);
    std::cout << *sig(0) << std::endl;
    sig.disconnect(&slots3);
    return 0;
}