public static member function
<thread>
std::thread::hardware_concurrency
static unsigned hardware_concurrency() noexcept;
Detect hardware concurrency
Returns the number of hardware thread contexts.
The interpretation of this value is system- and implementation- specific, and may not be exact, but just an approximation.
Note that this does not need to match the actual number of processors or cores available in the system: A system can support multiple threads per processing unit, or restrict the access to its resources to the program.
If this value is not computable or well defined, the function returns 0.
Return value
A hint on the number of hardware thread contexts.
Or zero, if this value is not computable or well defined.
Exception safety
No-throw guarantee: never throws exceptions.