From 055f7e2ec23f36e522e318a64eab414caba55e7e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Esteban=20K=C3=BCber?= <esteban@kuber.com.ar>
Date: Fri, 23 Aug 2019 13:45:18 -0700
Subject: [PATCH] Extend comment

---
 src/librustc_typeck/check/method/suggest.rs | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/librustc_typeck/check/method/suggest.rs b/src/librustc_typeck/check/method/suggest.rs
index 9f4fed23697a..440e7e5d0e31 100644
--- a/src/librustc_typeck/check/method/suggest.rs
+++ b/src/librustc_typeck/check/method/suggest.rs
@@ -747,7 +747,11 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         if let Node::GenericParam(ref param) = hir.get(id) {
                             match param.kind {
                                 hir::GenericParamKind::Type { synthetic: Some(_), .. } => {
-                                    impl_trait = true;  // #63706
+                                    // We've found `fn foo(x: impl Trait)` instead of
+                                    // `fn foo<T>(x: T)`. We want to suggest the correct
+                                    // `fn foo(x: impl Trait + TraitBound)` instead of
+                                    // `fn foo<T: TraitBound>(x: T)`. (#63706)
+                                    impl_trait = true;
                                     has_bounds = param.bounds.len() > 1;
                                 }
                                 _ => {