1 #![feature(array_windows)]
2 #![feature(control_flow_enum)]
4 #![recursion_limit = "256"]
5 #![allow(rustc::potential_query_instability)]
10 extern crate rustc_middle;
12 use rustc_hir::lang_items::LangItem;
13 use rustc_middle::traits;
14 use rustc_middle::ty::adjustment::CustomCoerceUnsized;
15 use rustc_middle::ty::query::Providers;
16 use rustc_middle::ty::{self, Ty, TyCtxt};
23 fn custom_coerce_unsize_info<'tcx>(
27 ) -> CustomCoerceUnsized {
28 let def_id = tcx.require_lang_item(LangItem::CoerceUnsized, None);
30 let trait_ref = ty::Binder::dummy(ty::TraitRef {
32 substs: tcx.mk_substs_trait(source_ty, &[target_ty.into()]),
35 match tcx.codegen_fulfill_obligation((ty::ParamEnv::reveal_all(), trait_ref)) {
36 Ok(traits::ImplSource::UserDefined(traits::ImplSourceUserDefinedData {
39 })) => tcx.coerce_unsized_info(impl_def_id).custom_kind.unwrap(),
41 bug!("invalid `CoerceUnsized` impl_source: {:?}", impl_source);
46 pub fn provide(providers: &mut Providers) {
47 partitioning::provide(providers);
48 polymorphize::provide(providers);