libmsgsl-dev binary package in Ubuntu Focal armhf

 The Guideline Support Library (GSL) contains functions and types that are
 suggested for use by the C++ Core Guidelines maintained by the Standard C++
 Foundation. This package contains Microsoft's implementation of GSL.
 .
 The library includes types like span<T>, string_span, owner<> and others.
 .
 The entire implementation is provided inline in the headers under the gsl
 directory. The implementation generally assumes a platform that implements
 C++14 support.

Source package