Remove redundant assertion near is_char_boundary.

diff --git a/src/libcollections/string.rs b/src/libcollections/string.rs
index ddde9d06d817667e494265c34506389ad968dfcf..fff7c160e31cd490259a82aa3f078a5d3a26cb69 100644 (file)
--- a/src/libcollections/string.rs
+++ b/src/libcollections/string.rs
@@ -1129,8 +1129,6 @@ pub fn remove(&mut self, idx: usize) -> char {
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn insert(&mut self, idx: usize, ch: char) {
-        let len = self.len();
-        assert!(idx <= len);
         assert!(self.is_char_boundary(idx));
         let mut bits = [0; 4];
         let bits = ch.encode_utf8(&mut bits).as_bytes();
@@ -1184,7 +1182,6 @@ unsafe fn insert_bytes(&mut self, idx: usize, bytes: &[u8]) {
                reason = "recent addition",
                issue = "35553")]
     pub fn insert_str(&mut self, idx: usize, string: &str) {
-        assert!(idx <= self.len());
         assert!(self.is_char_boundary(idx));
 
         unsafe {
@@ -1288,7 +1285,6 @@ pub fn is_empty(&self) -> bool {
     #[unstable(feature = "string_split_off", issue = "38080")]
     pub fn split_off(&mut self, mid: usize) -> String {
         assert!(self.is_char_boundary(mid));
-        assert!(mid <= self.len());
         let other = self.vec.split_off(mid);
         unsafe { String::from_utf8_unchecked(other) }
     }