From 2ce2d145c2cbcb93389dbea429d7e034ff367f48 Mon Sep 17 00:00:00 2001
From: Hirochika Matsumoto <matsujika@gmail.com>
Date: Sat, 30 Jan 2021 14:18:50 +0900
Subject: Account for union

---
 compiler/rustc_infer/src/infer/error_reporting/mod.rs | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

(limited to 'compiler')

diff --git a/compiler/rustc_infer/src/infer/error_reporting/mod.rs b/compiler/rustc_infer/src/infer/error_reporting/mod.rs
index 268819d3094..447b4f6d1e5 100644
--- a/compiler/rustc_infer/src/infer/error_reporting/mod.rs
+++ b/compiler/rustc_infer/src/infer/error_reporting/mod.rs
@@ -1842,13 +1842,20 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
             {
                 if let ObligationCauseCode::Pattern { span: Some(span), .. } = cause.code {
                     if let Ok(snippet) = self.tcx.sess.source_map().span_to_snippet(span) {
+                        let suggestion = if expected_def.is_struct() {
+                            format!("{}.{}", snippet, name)
+                        } else if expected_def.is_union() {
+                            format!("unsafe {{ {}.{} }}", snippet, name)
+                        } else {
+                            return;
+                        };
                         diag.span_suggestion(
                             span,
                             &format!(
                                 "you might have meant to use field `{}` of type `{}`",
                                 name, ty
                             ),
-                            format!("{}.{}", snippet, name),
+                            suggestion,
                             Applicability::MaybeIncorrect,
                         );
                     }
-- 
cgit 1.4.1-3-g733a5