Function rustdoc::html::render::cache::get_real_types

pub(crate) fn get_real_types<'tcx>(
    generics: &Generics, 
    arg: &Type, 
    tcx: TyCtxt<'tcx>, 
    recurse: i32, 
    res: &mut FxHashSet<(Type, TypeKind)>
) -> usize

The point of this function is to replace bounds with types.

i.e. [T, U] when you have the following bounds: T: Display, U: Option<T> will return [Display, Option] (we just returns the list of the types, we don’t care about the wrapped types in here).