drive by fix needless allocation of const string number

klensy · klensy · commit 68ea8ff16f74 · 2022-06-16T14:40:30.000+03:00
diff --git a/compiler/rustc_errors/src/emitter.rs b/compiler/rustc_errors/src/emitter.rs
@@ -771,8 +771,12 @@ impl EmitterWriter {
         self
     }
 
-    fn maybe_anonymized(&self, line_num: usize) -> String {
-        if self.ui_testing { ANONYMIZED_LINE_NUM.to_string() } else { line_num.to_string() }
+    fn maybe_anonymized(&self, line_num: usize) -> Cow<'static, str> {
+        if self.ui_testing {
+            Cow::Borrowed(ANONYMIZED_LINE_NUM)
+        } else {
+            Cow::Owned(line_num.to_string())
+        }
     }
 
     fn draw_line(

Original file line number	Diff line number	Diff line change
`@@ -771,8 +771,12 @@ impl EmitterWriter {`
`771`	`771`	`self`
`772`	`772`	`}`
`773`	`773`
`774`		`- fn maybe_anonymized(&self, line_num: usize) -> String {`
`775`		`- if self.ui_testing { ANONYMIZED_LINE_NUM.to_string() } else { line_num.to_string() }`
	`774`	`+ fn maybe_anonymized(&self, line_num: usize) -> Cow<'static, str> {`
	`775`	`+ if self.ui_testing {`
	`776`	`+ Cow::Borrowed(ANONYMIZED_LINE_NUM)`
	`777`	`+ } else {`
	`778`	`+ Cow::Owned(line_num.to_string())`
	`779`	`+ }`
`776`	`780`	`}`
`777`	`781`
`778`	`782`	`fn draw_line(`