Hi there,
I know very little C++, but have 25 years of C++ and C; including in mathematical applications/scenarios/projects.
I assume you are looking for a VC++ .EXE or DLL, as a built output, or is it just the raw equivalent C++ source files that you seek?
I should be able to help you, as most of the files only contains mathematical/arithmatical algorithms , and so should be straight-forward to convert to C++.
P.S. STL is not a dependency! it's a part of the C++ language, and is highly recommended you use STL container, which are highly optimised for speed/performance, and highly tested! No need to reinvent the wheel