c++怎么使用Folly库_c++高性能组件库功能与应用示例

#include <folly/Conv.h>
#include <iostream>
<p>int main() {
std::string str = "42";
int num = folly::to<int>(str); // 安全快速转换
std::cout << num * 2 << std::endl;
return 0;
}</p>

#include <folly/F14Map.h>
#include <iostream>
<p>int main() {
folly::F14FastMap<std::string, int> map;
map["apple"] = 1;
map["banana"] = 2;</p><p>for (const auto& [k, v] : map) {
std::cout << k << ": " << v << "\n";
}
return 0;
}</p>

#include <folly/futures/Future.h>
#include <thread>
#include <iostream>
<p>void asyncExample() {
auto [promise, future] = folly::makePromiseContract<std::string>();</p><p>std::thread t([p = std::move(promise)]() mutable {
std::this_thread::sleep_for(std::chrono::seconds(1));
p.setValue("Hello from future!");
});</p><p>future.thenValue([](std::string str) {
std::cout << str << std::endl;
}).wait();</p><p>t.join();
}</p>

#include <folly/Synchronized.h>
#include <vector>
#include <iostream>
<p>int main() {
folly::Synchronized<std::vector<int>> vec;</p><p>vec.withLock([](auto& v) {
v.push_back(1);
v.push_back(2);
});</p><p>auto copy = vec.copy();
for (int x : copy) std::cout << x << " ";
std::cout << std::endl;</p><p>return 0;
}</p>