core: Make range follow the for loop protocol

1 files changed, 5 insertions, 2 deletions

diff --git a/src/libcore/uint-template.rs b/src/libcore/uint-template.rs
index f9bffe3cc0f..e34fb145336 100644
--- a/src/libcore/uint-template.rs
+++ b/src/libcore/uint-template.rs
@@ -35,9 +35,12 @@ pure fn is_nonpositive(x: T) -> bool { x <= 0 as T }
 pure fn is_nonnegative(x: T) -> bool { x >= 0 as T }
 
 #[doc = "Iterate over the range [`lo`..`hi`)"]
-fn range(lo: T, hi: T, it: fn(T)) {
+fn range(lo: T, hi: T, it: fn(T) -> bool) {
     let mut i = lo;
-    while i < hi { it(i); i += 1 as T; }
+    while i < hi {
+        if !it(i) { break }
+        i += 1 as T;
+    }
 }
 
 #[doc = "Computes the bitwise complement"]