Boost
C++ Libraries
...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
This is an older version of Boost and was released in 2018. The current version is 1.89.0.
boost::process::std_err
// In header: <boost/process/io.hpp> unspecified std_err;
This property allows setting the stderr stream. The semantic and syntax is the same as for std_out .