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Xaeroxe · web-flow · commit 10384ab18a38 · 2017-09-18T10:15:17.000-06:00
diff --git a/src/liballoc/vec.rs b/src/liballoc/vec.rs
@@ -2694,6 +2694,9 @@ impl<'a, T, F> Iterator for DrainFilter<'a, T, F>
                     let del = self.del;
                     let src: *const T = &v[i];
                     let dst: *mut T = &mut v[i - del];
+                    // This is safe because self.vec has length 0
+                    // thus its elements will not have Drop::drop
+                    // called on them in the event of a panic.
                     ptr::copy_nonoverlapping(src, dst, 1);
                 }
             }

Original file line number	Diff line number	Diff line change
`@@ -2694,6 +2694,9 @@ impl<'a, T, F> Iterator for DrainFilter<'a, T, F>`
`2694`	`2694`	`let del = self.del;`
`2695`	`2695`	`let src: *const T = &v[i];`
`2696`	`2696`	`let dst: *mut T = &mut v[i - del];`
	`2697`	`+ // This is safe because self.vec has length 0`
	`2698`	`+ // thus its elements will not have Drop::drop`
	`2699`	`+ // called on them in the event of a panic.`
`2697`	`2700`	`ptr::copy_nonoverlapping(src, dst, 1);`
`2698`	`2701`	`}`
`2699`	`2702`	`}`