Rollup merge of #106980 - Nilstrieb:_use_mk_manual_debug_impl_instead, r=lcnr

Hide `_use_mk_alias_ty_instead` in `<AliasTy as Debug>::fmt`

2 files changed, 11 insertions, 2 deletions

diff --git a/compiler/rustc_middle/src/ty/structural_impls.rs b/compiler/rustc_middle/src/ty/structural_impls.rs
index d2acfac6188..81ec18684fd 100644
--- a/compiler/rustc_middle/src/ty/structural_impls.rs
+++ b/compiler/rustc_middle/src/ty/structural_impls.rs
@@ -7,7 +7,7 @@ use crate::mir::{Field, ProjectionKind};
 use crate::ty::fold::{FallibleTypeFolder, TypeFoldable, TypeSuperFoldable};
 use crate::ty::print::{with_no_trimmed_paths, FmtPrinter, Printer};
 use crate::ty::visit::{TypeSuperVisitable, TypeVisitable, TypeVisitor};
-use crate::ty::{self, InferConst, Lift, Term, TermKind, Ty, TyCtxt};
+use crate::ty::{self, AliasTy, InferConst, Lift, Term, TermKind, Ty, TyCtxt};
 use rustc_data_structures::functor::IdFunctor;
 use rustc_hir::def::Namespace;
 use rustc_index::vec::{Idx, IndexVec};
@@ -180,6 +180,15 @@ impl<'tcx> fmt::Debug for ty::PredicateKind<'tcx> {
     }
 }
 
+impl<'tcx> fmt::Debug for AliasTy<'tcx> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("AliasTy")
+            .field("substs", &self.substs)
+            .field("def_id", &self.def_id)
+            .finish()
+    }
+}
+
 ///////////////////////////////////////////////////////////////////////////
 // Atomic structs
 //
diff --git a/compiler/rustc_middle/src/ty/sty.rs b/compiler/rustc_middle/src/ty/sty.rs
index b5bb9238512..3f8252aefdc 100644
--- a/compiler/rustc_middle/src/ty/sty.rs
+++ b/compiler/rustc_middle/src/ty/sty.rs
@@ -1226,7 +1226,7 @@ impl<'tcx> FallibleTypeFolder<'tcx> for SkipBindersAt<'tcx> {
 /// For a projection, this would be `<Ty as Trait<...>>::N`.
 ///
 /// For an opaque type, there is no explicit syntax.
-#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Debug, TyEncodable, TyDecodable)]
+#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, TyEncodable, TyDecodable)]
 #[derive(HashStable, TypeFoldable, TypeVisitable, Lift)]
 pub struct AliasTy<'tcx> {
     /// The parameters of the associated or opaque item.