X-Git-Url: https://git.lizzy.rs/?a=blobdiff_plain;f=compiler%2Frustc_trait_selection%2Fsrc%2Ftraits%2Fselect%2Fmod.rs;h=49bb3d03621f3379a844c8162383b5a8b0ea285a;hb=0f2e45b18f47c9cb93267a82ed685f5d37f79367;hp=de158a15d54b8563d1c514e287744bf5c24103f7;hpb=a3c0a023611fcaf5ae3ec242d7d60e356041d25f;p=rust.git

diff --git a/compiler/rustc_trait_selection/src/traits/select/mod.rs b/compiler/rustc_trait_selection/src/traits/select/mod.rs
index de158a15d54..49bb3d03621 100644
--- a/compiler/rustc_trait_selection/src/traits/select/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/mod.rs
@@ -959,7 +959,10 @@ pub(crate) fn coinductive_match<I>(&mut self, mut cycle: I) -> bool
 
     fn coinductive_predicate(&self, predicate: ty::Predicate<'tcx>) -> bool {
         let result = match predicate.kind().skip_binder() {
-            ty::PredicateKind::Trait(ref data) => self.tcx().trait_is_auto(data.def_id()),
+            ty::PredicateKind::Trait(ref data) => {
+                self.tcx().trait_is_auto(data.def_id())
+                    || self.tcx().lang_items().sized_trait() == Some(data.def_id())
+            }
             ty::PredicateKind::WellFormed(_) => true,
             _ => false,
         };