Add rustc_on_unimplemented to Subst

rust-lang · May 14, 2022 · 06a1e88 · 06a1e88
1 parent 91afd02
commit 06a1e88
Showing 1 changed file with 1 addition and 0 deletions.
diff --git a/compiler/rustc_middle/src/ty/subst.rs b/compiler/rustc_middle/src/ty/subst.rs
@@ -499,6 +499,7 @@ impl<'tcx> TypeFoldable<'tcx> for &'tcx ty::List<Ty<'tcx>> {
 }
 
 // Just call `foo.subst(tcx, substs)` to perform a substitution across `foo`.
+#[rustc_on_unimplemented(message = "Calling `subst` must now be done through an `EarlyBinder`")]
 pub trait Subst<'tcx>: Sized {
     type Inner;