Someone more experienced at C can jump in and correct me but from my understanding you're correct, you download the files. You could use git to create subrepos for dependencies in a directory in your project, too. When I've asked this question before those were the answers I got.
Alifatisk|2 years ago
I’m too used to Ruby and how gems are installed, I think I’m looking for a similar experience in C where you find the lib you want, install it and include it in your code.
eddtests|2 years ago
Edit: I saw a project recently written in C++ and they had subrepos in a `deps/` directory and then linked to those, so it was all manually managed. If I were to make a new project in C++ I think that's how I'd go too.