std::thread::hardware_concurrency

static unsigned hardware_concurrency();

Returns the number of concurrent threads supported by the implementation. The value should be considered only a hint.

Parameters

(none).

Return value

number of concurrent threads supported. If the value is not well defined or not computable, returns ​0​.

Exceptions

Example

#include <iostream>
#include <thread>
 
int main() {
    unsigned int n = std::thread::hardware_concurrency();
    std::cout << n << " concurrent threads are supported.\n";
}

4 concurrent threads are supported.