Try to compile it with that compiler settings:


g++ –std=c++14 -pthread 


Hint comes from here:
https://www.geeksforgeeks.org/thread-hardware_concurrency-function-in-c/amp/

Sent from my iPhone

On 24.08.2019, at 20:05, Adrian C via Boost-users <boost-users@lists.boost.org> wrote:

undefined reference to `std::thread::hardware_concurrency()'