32 Thread support library [thread]

32.5 Mutual exclusion [thread.mutex]

32.5.3 Header <shared_mutex> synopsis [shared.mutex.syn]

namespace std { class shared_mutex; class shared_timed_mutex; template<class Mutex> class shared_lock; template<class Mutex> void swap(shared_lock<Mutex>& x, shared_lock<Mutex>& y) noexcept; }