c++响应式编程 rxcpp之cep样例解析

#include "rxcpp/rx.hpp"

#include <thread>

// create alias' to simplify code
// these are owned by the user so that
// conflicts can be managed by the user.
//创建别名以简化代码
//这一步由用户处理   用户可以处理因此带来的冲突
namespace rx = rxcpp;
namespace rxsub = rxcpp::subjects;
namespace rxu = rxcpp::util;

#include <cctype>
#include <clocale>

// At this time, RxCpp will fail to compile if the contents
// of the std namespace are merged into the global namespace
// DO NOT USE: 'using namespace std;'
// 不要用'using namespace std;'，反之，Rxcpp将编译失败
int main()
{
    auto keys = rx::observable<>::create<int>(//创建一个简单的可观察数字集合
        [](rx::subscriber<int> dest) {
            for (;;) {//被观察者循环检测用户输入字符
                std::cout << "threadid observable: " << std::this_thread::get_id() << std::endl;
                int key = std::cin.get();
                dest.on_next(key);//通知观察者处理字符
            }
        }).
        publish();//发布订阅

        auto a = keys.
            filter([](int key) {return std::tolower(key) == 'a'; });//过滤器 过滤字符'a'

        auto g = keys.
            filter([](int key) {return std::tolower(key) == 'g'; });//过滤器 过滤字符'b'

        auto observer = a.merge(g).//过滤器合并
            subscribe([](int key) {//观察者使用 Observable 类的 Subscribe 方法订阅可观察集合
            std::cout << "threadid observer: " << std::this_thread::get_id() << std::endl;
            std::cout << key << std::endl;
                });
        //observer.unsubscribe(); //可取消订阅
        // run the loop in create //开启循环
        keys.connect();
        return 0;
}