diff options
| -rw-r--r-- | src/libcollections/string.rs | 12 | ||||
| -rw-r--r-- | src/libcollectionstest/string.rs | 2 |
2 files changed, 9 insertions, 5 deletions
diff --git a/src/libcollections/string.rs b/src/libcollections/string.rs index 2226116585f..306fad2328b 100644 --- a/src/libcollections/string.rs +++ b/src/libcollections/string.rs @@ -992,10 +992,12 @@ impl String { /// Shortens this `String` to the specified length. /// + /// If `new_len` is greater than the string's current length, this has no + /// effect. + /// /// # Panics /// - /// Panics if `new_len` > current length, or if `new_len` does not lie on a - /// [`char`] boundary. + /// Panics if `new_len` does not lie on a [`char`] boundary. /// /// [`char`]: ../../std/primitive.char.html /// @@ -1013,8 +1015,10 @@ impl String { #[inline] #[stable(feature = "rust1", since = "1.0.0")] pub fn truncate(&mut self, new_len: usize) { - assert!(self.is_char_boundary(new_len)); - self.vec.truncate(new_len) + if new_len <= self.len() { + assert!(self.is_char_boundary(new_len)); + self.vec.truncate(new_len) + } } /// Removes the last character from the string buffer and returns it. diff --git a/src/libcollectionstest/string.rs b/src/libcollectionstest/string.rs index d8e01f3800c..d71529023f4 100644 --- a/src/libcollectionstest/string.rs +++ b/src/libcollectionstest/string.rs @@ -248,10 +248,10 @@ fn test_str_truncate() { } #[test] -#[should_panic] fn test_str_truncate_invalid_len() { let mut s = String::from("12345"); s.truncate(6); + assert_eq!(s, "12345"); } #[test] |