From b17b20cafc87193dace2beb1cdb0e126d944f8e3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Esteban=20K=C3=BCber?= <esteban@kuber.com.ar>
Date: Mon, 4 May 2020 11:09:10 -0700
Subject: [PATCH] Add docstring to `deny_equality_constraints`

---
 src/librustc_ast_passes/ast_validation.rs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/librustc_ast_passes/ast_validation.rs b/src/librustc_ast_passes/ast_validation.rs
index 5f47c9eb2c2a6..cc88fbb295c68 100644
--- a/src/librustc_ast_passes/ast_validation.rs
+++ b/src/librustc_ast_passes/ast_validation.rs
@@ -1291,6 +1291,8 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
     }
 }
 
+/// When encountering an equality constraint in a `where` clause, emit an error. If the code seems
+/// like it's setting an associated type, provide an appropriate suggestion.
 fn deny_equality_constraints(
     this: &mut AstValidator<'_>,
     predicate: &WhereEqPredicate,