30 Thread support library [thread]

30.3 Threads [thread.threads]

30.3.1 Class thread [thread.thread.class]

30.3.1.6 thread static members [thread.thread.static]

unsigned hardware_concurrency() noexcept;

1

Returns: The number of hardware thread contexts. [ Note: This value should only be considered to be a hint.  — end note ] If this value is not computable or well defined an implementation should return 0.