Function contains_ty_adt_constructor_opaque 

pub fn contains_ty_adt_constructor_opaque<'tcx>(
    cx: &LateContext<'tcx>,
    ty: Ty<'tcx>,
    needle: Ty<'tcx>,
) -> bool

Walks into ty and returns true if any inner type is an instance of the given type, or adt constructor of the same type.

This method also recurses into opaque type predicates, so call it with impl Trait<U> and U will also return true.