Function check_drop_impl

pub fn check_drop_impl(
    tcx: TyCtxt<'_>,
    drop_impl_did: DefId,
) -> Result<(), ErrorGuaranteed>

This function confirms that the Drop implementation identified by drop_impl_did is not any more specialized than the type it is attached to (Issue #8142).

This means:

1. The self type must be nominal (this is already checked during coherence),

2. The generic region/type parameters of the impl’s self type must all be parameters of the Drop impl itself (i.e., no specialization like impl Drop for Foo<i32>), and,

3. Any bounds on the generic parameters must be reflected in the struct/enum definition for the nominal type itself (i.e. cannot do struct S<T>; impl<T:Clone> Drop for S<T> { ... }).