---

yaml
---
r: 12522
b: refs/heads/master
c: 75cf13e
h: refs/heads/master
v: v3

Author: graydon

[refs]

@@ -1,5 +1,5 @@
 ---
-refs/heads/master: 956bc773c684fe0f9e3ebc165cadb0b02d918805
+refs/heads/master: 75cf13ec7279ff7a56e3329ab6d6d8fc03e66e4f
 refs/heads/snap-stage1: e33de59e47c5076a89eadeb38f4934f58a3618a6
 refs/heads/snap-stage3: 4a81779abd786ff22d71434c6d9a5917ea4cdfff
 refs/heads/try: 2898dcc5d97da9427ac367542382b6239d9c0bbf

trunk/src/libcore/str.rs

@@ -1539,6 +1539,21 @@ fn as_c_str<T>(s: str, f: fn(*libc::c_char) -> T) -> T unsafe {
     as_buf(s) {|buf| f(buf as *libc::c_char) }
 }
 
+
+#[doc = "
+Work with the byte buffer and length of a slice.
+
+The unpacked length is one byte longer than the 'official' indexable
+length of the string. This is to permit probing the byte past the
+indexable area for a null byte, as is the case in slices pointing
+to full strings, or suffixes of them.
+"]
+fn unpack_slice<T>(s: str/&, f: fn(*u8, uint) -> T) -> T unsafe {
+    let v : *(*u8,uint) = ::unsafe::reinterpret_cast(ptr::addr_of(s));
+    let (buf,len) = *v;
+    f(buf, len)
+}
+
 #[doc = "
 Reserves capacity for exactly `n` bytes in the given string, not including
 the null terminator.
@@ -2706,4 +2721,16 @@ mod tests {
         }
         assert found_b;
     }
+
+    #[test]
+    fn test_unpack_slice() unsafe {
+        let a = "hello";
+        unpack_slice(a) {|buf, len|
+            assert a[0] == 'h' as u8;
+            assert *buf == 'h' as u8;
+            assert len == 6u;
+            assert *ptr::offset(buf,4u) == 'o' as u8;
+            assert *ptr::offset(buf,5u) == 0u8;
+        }
+    }
 }