Use inner iterator may_have_side_effect for Cloned

KamilaBorowska · KamilaBorowska · commit 3eddc743f2ca · 2018-12-05T16:48:34.000+01:00
Previous implementation wasn't correct, as an inner iterator
could have had side effects.
diff --git a/src/libcore/iter/mod.rs b/src/libcore/iter/mod.rs
@@ -602,7 +602,9 @@ unsafe impl<'a, I, T: 'a> TrustedRandomAccess for Cloned<I>
     }
 
     #[inline]
-    fn may_have_side_effect() -> bool { false }
+    fn may_have_side_effect() -> bool {
+        I::may_have_side_effect()
+    }
 }
 
 #[unstable(feature = "trusted_len", issue = "37572")]

Original file line number	Diff line number	Diff line change
`@@ -602,7 +602,9 @@ unsafe impl<'a, I, T: 'a> TrustedRandomAccess for Cloned<I>`
`602`	`602`	`}`
`603`	`603`
`604`	`604`	`#[inline]`
`605`		`- fn may_have_side_effect() -> bool { false }`
	`605`	`+ fn may_have_side_effect() -> bool {`
	`606`	`+ I::may_have_side_effect()`
	`607`	`+ }`
`606`	`608`	`}`
`607`	`609`
`608`	`610`	`#[unstable(feature = "trusted_len", issue = "37572")]`