Function ra_ap_hir_ty::method_resolution::resolve_indexing_op

pub fn resolve_indexing_op(
    db: &dyn HirDatabase, 
    ty: &Canonical<Ty>, 
    env: Arc<TraitEnvironment>, 
    krate: CrateId, 
    index_trait: TraitId
) -> Option<Canonical<Ty>>

Returns the self type for the index trait call.