std::thread::hardware_concurrency (3) - Linux Manuals

std::thread::hardware_concurrency: std::thread::hardware_concurrency

NAME

std::thread::hardware_concurrency - std::thread::hardware_concurrency

Synopsis

static unsigned int hardware_concurrency() noexcept; (since C++11)

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.

Example

// Run this code

  #include <iostream>
  #include <thread>

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

Possible output:

  4 concurrent threads are supported.