1 #![feature(array_windows)]
2 #![feature(bool_to_option)]
3 #![feature(crate_visibility_modifier)]
4 #![feature(control_flow_enum)]
6 #![recursion_limit = "256"]
11 extern crate rustc_middle;
13 use rustc_hir::lang_items::LangItem;
14 use rustc_middle::traits;
15 use rustc_middle::ty::adjustment::CustomCoerceUnsized;
16 use rustc_middle::ty::query::Providers;
17 use rustc_middle::ty::{self, Ty, TyCtxt};
24 fn custom_coerce_unsize_info<'tcx>(
28 ) -> CustomCoerceUnsized {
29 let def_id = tcx.require_lang_item(LangItem::CoerceUnsized, None);
31 let trait_ref = ty::Binder::dummy(ty::TraitRef {
33 substs: tcx.mk_substs_trait(source_ty, &[target_ty.into()]),
36 match tcx.codegen_fulfill_obligation((ty::ParamEnv::reveal_all(), trait_ref)) {
37 Ok(traits::ImplSource::UserDefined(traits::ImplSourceUserDefinedData {
40 })) => tcx.coerce_unsized_info(impl_def_id).custom_kind.unwrap(),
42 bug!("invalid `CoerceUnsized` impl_source: {:?}", impl_source);
47 pub fn provide(providers: &mut Providers) {
48 partitioning::provide(providers);
49 polymorphize::provide(providers);