Function implementors 

fn implementors(
    facade: &[SourceFile],
    core: &[SourceFile],
) -> BTreeMap<String, BTreeSet<String>>

Every pub type in the two crates that implements one of the catalogued traits, as trait name → type names.

A non-pub type is skipped: AlwaysPrune, CountingSampler and BrokenStorage all implement these traits and are test doubles, not API.