New upstream version 1.14.0+dfsg1

[rustc.git] / src / libcore / iter_private.rs

diff --git a/src/libcore/iter_private.rs b/src/libcore/iter_private.rs
index 83eeef31ab054cd074c3fa515a78f6ead1401594..bc1aaa09f3dbd35d3f566c667dc896564b591ce5 100644 (file)
--- a/src/libcore/iter_private.rs
+++ b/src/libcore/iter_private.rs
@@ -14,6 +14,7 @@
 /// # Safety
 ///
 /// The iterator's .len() and size_hint() must be exact.
+/// `.len()` must be cheap to call.
 ///
 /// .get_unchecked() must return distinct mutable references for distinct
 /// indices (if applicable), and must return a valid reference if index is in
@@ -21,5 +22,7 @@
 #[doc(hidden)]
 pub unsafe trait TrustedRandomAccess : ExactSizeIterator {
     unsafe fn get_unchecked(&mut self, i: usize) -> Self::Item;
+    /// Return `true` if getting an iterator element may have
+    /// side effects. Remember to take inner iterators into account.
+    fn may_have_side_effect() -> bool;
 }
-