PhoenixThread  1.8.7
Set of functions to ease parallelisation in C++11 and can be used in modern C++
Set of functions to ease parallelisation in C++11 and can be used in modern C++

I agree, it is for old softwares, because C++17 or C++14 are much better. This is to be compilent with stupid people...

See test coverage detail from gcovr
See test coverage report