One thing I'm missing in the Rust ecosystem of bindings to C libraries is easy conditional compilation based on the build-time library version. Something like the GTK_CHECK_VERSION() macros in C.
In Rust bindings, it's common to expose some baseline version API, then have feature flags to expose (and depend on) newer versions of the library. But there's no simple way to do, as a downstream user:
#[cfg(have_gtk_4_12)]
use_new_api();
#[cfg(not(have_gtk_4_12))]
fallback_with_old_api();
Related: how do distros track these build-time dependency checks? E.g. my app did a build-time check and used the GTK < 4.12 code path, then the distro updated GTK to 4.12, so now my app needs to be rebuilt to take advantage of the new API. How is this tracked?
I guess this question is more relevant for rolling-release distros, but it's very possible for a build-time check to test for a minor version which would be updated even in a non-rolling-release distro.
