Use unreachable_unchecked in const_panic_fmt.

m-ou-se · m-ou-se · commit b48274fd98b7 · 2021-07-28T16:12:30.000+02:00
diff --git a/library/core/src/panicking.rs b/library/core/src/panicking.rs
@@ -100,7 +100,10 @@ pub const fn const_panic_fmt(fmt: fmt::Arguments<'_>) -> ! {
     if let Some(msg) = fmt.as_str() {
         panic_str(msg);
     } else {
-        panic_str("???");
+        // SAFETY: This is only evaluated at compile time, which handles this
+        // fine (in case it turns out this branch turns out to be reachable
+        // somehow).
+        unsafe { crate::hint::unreachable_unchecked() };
     }
 }
 

Original file line number	Diff line number	Diff line change
`@@ -100,7 +100,10 @@ pub const fn const_panic_fmt(fmt: fmt::Arguments<'_>) -> ! {`
`100`	`100`	`if let Some(msg) = fmt.as_str() {`
`101`	`101`	`panic_str(msg);`
`102`	`102`	`} else {`
`103`		`- panic_str("???");`
	`103`	`+ // SAFETY: This is only evaluated at compile time, which handles this`
	`104`	`+ // fine (in case it turns out this branch turns out to be reachable`
	`105`	`+ // somehow).`
	`106`	`+ unsafe { crate::hint::unreachable_unchecked() };`
`104`	`107`	`}`
`105`	`108`	`}`
`106`	`109`