15.1 Header <experimental/timer> synopsis [timer.synop]
#include <chrono>
namespace std {
namespace experimental {
namespace net {
inline namespace v1 {
template<class Clock> struct wait_traits;
template<class Clock, class WaitTraits = wait_traits<Clock>>
class basic_waitable_timer;
using system_timer = basic_waitable_timer<chrono::system_clock>;
using steady_timer = basic_waitable_timer<chrono::steady_clock>;
using high_resolution_timer = basic_waitable_timer<chrono::high_resolution_clock>;
} } } }