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();

#rust