The Guidelines Support Library (GSL) contains functions and types that are
suggested for use by the C++ Core Guidelines maintained by the Standard C++
Foundation. This repo contains Microsoft's implementation of GSL.

The entire implementation is provided inline in the headers under the gsl
directory. The implementation generally assumes a platform that implements
C++14 support.

While some types have been broken out into their own headers (e.g. gsl/span),
it is simplest to just include gsl/gsl and gain access to the entire library.