---

yaml
---
r: 123443
b: refs/heads/auto
c: 3c7f619
h: refs/heads/master
i:
  123441: 7824b8d
  123439: 31b6a60
v: v3

Author: emberian

[refs]

@@ -13,7 +13,7 @@ refs/heads/try3: 9387340aab40a73e8424c48fd42f0c521a4875c0
 refs/tags/release-0.3.1: 495bae036dfe5ec6ceafd3312b4dca48741e845b
 refs/tags/release-0.4: e828ea2080499553b97dfe33b3f4d472b4562ad7
 refs/tags/release-0.5: 7e3bcfbf21278251ee936ad53e92e9b719702d73
-refs/heads/auto: c2dd553bed572368953801dd1d339013f58b53d6
+refs/heads/auto: 3c7f619b76b87c400e270eebfa7625844afcd673
 refs/heads/servo: af82457af293e2a842ba6b7759b70288da276167
 refs/tags/release-0.6: b4ebcfa1812664df5e142f0134a5faea3918544c
 refs/tags/0.1: b19db808c2793fe2976759b85a355c3ad8c8b336

branches/auto/src/libcore/str.rs

@@ -1764,7 +1764,9 @@ impl<'a> StrSlice<'a> for &'a str {
 
     #[inline]
     fn slice(&self, begin: uint, end: uint) -> &'a str {
-        assert!(self.is_char_boundary(begin) && self.is_char_boundary(end));
+        assert!(self.is_char_boundary(begin) && self.is_char_boundary(end),
+                "index {} and/or {} in `{}` do not lie on character boundary", begin,
+                end, *self);
         unsafe { raw::slice_bytes(*self, begin, end) }
     }
 
@@ -1775,7 +1777,8 @@ impl<'a> StrSlice<'a> for &'a str {
 
     #[inline]
     fn slice_to(&self, end: uint) -> &'a str {
-        assert!(self.is_char_boundary(end));
+        assert!(self.is_char_boundary(end), "index {} in `{}` does not lie on \
+                a character boundary", end, *self);
         unsafe { raw::slice_bytes(*self, 0, end) }
     }