Function rustc_typeck::collect::get_new_lifetime_name

fn get_new_lifetime_name<'tcx>(
    tcx: TyCtxt<'tcx>, 
    poly_trait_ref: PolyTraitRef<'tcx>, 
    generics: &Generics<'tcx>
) -> String

Synthesize a new lifetime name that doesn’t clash with any of the lifetimes already present.