> header only libraries don't really have an ABI This one is not really a header only library. It becomes a source file when you define a macro, to compile alo

> header only libraries don't really have an ABI This one is not really a header only library. It becomes a source file when you define a macro, to compile along your other source files. If you build a shared library with it, it makes sense to set the default symbol visibility to be hidden, so it wouldn't clash with actual glib pulled in from some other shared library. But you can't easily do the same if you build a static library. And if you expose any function with GHashTable, GList or GString in its signature, you really want them to be binary compatible with actual Glib. It's not true that header-only libraries don't have ABIs.