C ++ multithreading. Part of iterater is replaced by auto and mutex is used.

[Cpp] # include <iostream> # include <chrono> # include <thread> # include <mutex> # include <map> # include <string> using namespace std; map <string, string> g_pages; mutex g_pages_mutex; void save_page (const string & url) {// simulate a long page fetch this_thread: sleep_for (chrono :: seconds (1); string result = "fake content"; g_pages_mutex.lock (); g_pages [url] = result; g_pages_mutex.unlock ();} int m Ain () {thread t1 (save_page, "http: // foo"); thread t2 (save_page, "http: // bar"); t1.join (); t2.join (); g_pages_mutex.lock (); // not necessary as the threads are joined, but good style for (auto iter = g_pages.begin (); iter! = G_pages.end (); iter ++) {cout <iter-> first <"=>" <iter-> second <'\ n ';} g_pages_mutex.unlock (); // again, good style system ("pause");} if you add a map <string, string >:: iterater iter, if the declaration is used, auto is not needed. The preceding section also demonstrates the multithreading feature of c ++ 11. Mutex is used. (Fortunately, I learned the operating system and understood the concept of thread mutex .) Of course it can be simpler, just like C #'s foreach. (Of course I have never touched C #) the following changes: [cpp] for (auto pair: g_pages) {cout <pair. first <"=>" <pair. second <'\ n';} does not write the result. They are all the same and the implementation method is different.