large, well-maintained set of C++ libraries
Knowing how to leverage other people's code is a valuable programming skill. The Boost libraries for C++ are extensive and cover many common programming needs. They can be compiled from source or installed with a package manager if offered by your operating system's package repository.
Boost comprises over one hundred independent libraries. One example is Boost.MPI. It provides a high-level, user-friendly wrapper to existing C-based implementations of the Message Passing Interface (MPI). Message passing allows information to be shared among processes in parallel computing.
A second example is Boost.Program_options, which facilitates the use of command line arguments when running a C++ program. Its operation is similar to that of argparse in Python programming.