std: unify the str -> [u8] functions as 3 methods: .as_bytes() and .as_bytes_with_null[_consume]().

The first acts on &str and is not nul-terminated, the last two act on strings
that are always null terminated (&'static str, ~str and @str).

12 files changed, 188 insertions, 137 deletions

diff --git a/src/libstd/io.rs b/src/libstd/io.rs
index 142489df6c1..07e129e3c28 100644
--- a/src/libstd/io.rs
+++ b/src/libstd/io.rs
@@ -1091,7 +1091,7 @@ pub fn with_bytes_reader<T>(bytes: &[u8], f: &fn(@Reader) -> T) -> T {
 }
 
 pub fn with_str_reader<T>(s: &str, f: &fn(@Reader) -> T) -> T {
-    str::byte_slice(s, |bytes| with_bytes_reader(bytes, f))
+    with_bytes_reader(s.as_bytes(), f)
 }
 
 // Writing
@@ -1462,7 +1462,7 @@ impl<T:Writer> WriterUtil for T {
             self.write_str(str::from_char(ch));
         }
     }
-    fn write_str(&self, s: &str) { str::byte_slice(s, |v| self.write(v)) }
+    fn write_str(&self, s: &str) { self.write(s.as_bytes()) }
     fn write_line(&self, s: &str) {
         self.write_str(s);
         self.write_str(&"\n");
diff --git a/src/libstd/num/int_macros.rs b/src/libstd/num/int_macros.rs
index 3583e2f366f..74f74d11b73 100644
--- a/src/libstd/num/int_macros.rs
+++ b/src/libstd/num/int_macros.rs
@@ -793,27 +793,27 @@ mod tests {
 
     #[test]
     fn test_parse_bytes() {
-        use str::to_bytes;
-        assert_eq!(parse_bytes(to_bytes("123"), 10u), Some(123 as $T));
-        assert_eq!(parse_bytes(to_bytes("1001"), 2u), Some(9 as $T));
-        assert_eq!(parse_bytes(to_bytes("123"), 8u), Some(83 as $T));
-        assert_eq!(i32::parse_bytes(to_bytes("123"), 16u), Some(291 as i32));
-        assert_eq!(i32::parse_bytes(to_bytes("ffff"), 16u), Some(65535 as i32));
-        assert_eq!(i32::parse_bytes(to_bytes("FFFF"), 16u), Some(65535 as i32));
-        assert_eq!(parse_bytes(to_bytes("z"), 36u), Some(35 as $T));
-        assert_eq!(parse_bytes(to_bytes("Z"), 36u), Some(35 as $T));
-
-        assert_eq!(parse_bytes(to_bytes("-123"), 10u), Some(-123 as $T));
-        assert_eq!(parse_bytes(to_bytes("-1001"), 2u), Some(-9 as $T));
-        assert_eq!(parse_bytes(to_bytes("-123"), 8u), Some(-83 as $T));
-        assert_eq!(i32::parse_bytes(to_bytes("-123"), 16u), Some(-291 as i32));
-        assert_eq!(i32::parse_bytes(to_bytes("-ffff"), 16u), Some(-65535 as i32));
-        assert_eq!(i32::parse_bytes(to_bytes("-FFFF"), 16u), Some(-65535 as i32));
-        assert_eq!(parse_bytes(to_bytes("-z"), 36u), Some(-35 as $T));
-        assert_eq!(parse_bytes(to_bytes("-Z"), 36u), Some(-35 as $T));
-
-        assert!(parse_bytes(to_bytes("Z"), 35u).is_none());
-        assert!(parse_bytes(to_bytes("-9"), 2u).is_none());
+        use str::StrSlice;
+        assert_eq!(parse_bytes("123".as_bytes(), 10u), Some(123 as $T));
+        assert_eq!(parse_bytes("1001".as_bytes(), 2u), Some(9 as $T));
+        assert_eq!(parse_bytes("123".as_bytes(), 8u), Some(83 as $T));
+        assert_eq!(i32::parse_bytes("123".as_bytes(), 16u), Some(291 as i32));
+        assert_eq!(i32::parse_bytes("ffff".as_bytes(), 16u), Some(65535 as i32));
+        assert_eq!(i32::parse_bytes("FFFF".as_bytes(), 16u), Some(65535 as i32));
+        assert_eq!(parse_bytes("z".as_bytes(), 36u), Some(35 as $T));
+        assert_eq!(parse_bytes("Z".as_bytes(), 36u), Some(35 as $T));
+
+        assert_eq!(parse_bytes("-123".as_bytes(), 10u), Some(-123 as $T));
+        assert_eq!(parse_bytes("-1001".as_bytes(), 2u), Some(-9 as $T));
+        assert_eq!(parse_bytes("-123".as_bytes(), 8u), Some(-83 as $T));
+        assert_eq!(i32::parse_bytes("-123".as_bytes(), 16u), Some(-291 as i32));
+        assert_eq!(i32::parse_bytes("-ffff".as_bytes(), 16u), Some(-65535 as i32));
+        assert_eq!(i32::parse_bytes("-FFFF".as_bytes(), 16u), Some(-65535 as i32));
+        assert_eq!(parse_bytes("-z".as_bytes(), 36u), Some(-35 as $T));
+        assert_eq!(parse_bytes("-Z".as_bytes(), 36u), Some(-35 as $T));
+
+        assert!(parse_bytes("Z".as_bytes(), 35u).is_none());
+        assert!(parse_bytes("-9".as_bytes(), 2u).is_none());
     }
 
     #[test]
diff --git a/src/libstd/num/strconv.rs b/src/libstd/num/strconv.rs
index 30efe9a3922..3905d82cd0f 100644
--- a/src/libstd/num/strconv.rs
+++ b/src/libstd/num/strconv.rs
@@ -16,6 +16,7 @@ use ops::{Add, Sub, Mul, Div, Rem, Neg};
 use option::{None, Option, Some};
 use char;
 use str;
+use str::{StrSlice};
 use kinds::Copy;
 use vec;
 use vec::{CopyableVector, ImmutableVector};
@@ -189,18 +190,18 @@ pub fn to_str_bytes_common<T:NumCast+Zero+One+Eq+Ord+NumStrConv+Copy+
     let _1: T = One::one();
 
     if is_NaN(num) {
-        return (str::to_bytes("NaN"), true);
+        return ("NaN".as_bytes().to_owned(), true);
     }
     else if is_inf(num){
         return match sign {
-            SignAll => (str::to_bytes("+inf"), true),
-            _       => (str::to_bytes("inf"), true)
+            SignAll => ("+inf".as_bytes().to_owned(), true),
+            _       => ("inf".as_bytes().to_owned(), true)
         }
     }
     else if is_neg_inf(num) {
         return match sign {
-            SignNone => (str::to_bytes("inf"), true),
-            _        => (str::to_bytes("-inf"), true),
+            SignNone => ("inf".as_bytes().to_owned(), true),
+            _        => ("-inf".as_bytes().to_owned(), true),
         }
     }
 
@@ -638,7 +639,7 @@ pub fn from_str_common<T:NumCast+Zero+One+Eq+Ord+Copy+Div<T,T>+Mul<T,T>+
         special: bool, exponent: ExponentFormat, empty_zero: bool,
         ignore_underscores: bool
         ) -> Option<T> {
-    from_str_bytes_common(str::to_bytes(buf), radix, negative,
+    from_str_bytes_common(buf.as_bytes(), radix, negative,
                           fractional, special, exponent, empty_zero,
                           ignore_underscores)
 }
diff --git a/src/libstd/num/uint_macros.rs b/src/libstd/num/uint_macros.rs
index a7aebf1f176..2bc1ca9c673 100644
--- a/src/libstd/num/uint_macros.rs
+++ b/src/libstd/num/uint_macros.rs
@@ -538,16 +538,16 @@ mod tests {
 
     #[test]
     pub fn test_parse_bytes() {
-        use str::to_bytes;
-        assert_eq!(parse_bytes(to_bytes("123"), 10u), Some(123u as $T));
-        assert_eq!(parse_bytes(to_bytes("1001"), 2u), Some(9u as $T));
-        assert_eq!(parse_bytes(to_bytes("123"), 8u), Some(83u as $T));
-        assert_eq!(u16::parse_bytes(to_bytes("123"), 16u), Some(291u as u16));
-        assert_eq!(u16::parse_bytes(to_bytes("ffff"), 16u), Some(65535u as u16));
-        assert_eq!(parse_bytes(to_bytes("z"), 36u), Some(35u as $T));
-
-        assert!(parse_bytes(to_bytes("Z"), 10u).is_none());
-        assert!(parse_bytes(to_bytes("_"), 2u).is_none());
+        use str::StrSlice;
+        assert_eq!(parse_bytes("123".as_bytes(), 10u), Some(123u as $T));
+        assert_eq!(parse_bytes("1001".as_bytes(), 2u), Some(9u as $T));
+        assert_eq!(parse_bytes("123".as_bytes(), 8u), Some(83u as $T));
+        assert_eq!(u16::parse_bytes("123".as_bytes(), 16u), Some(291u as u16));
+        assert_eq!(u16::parse_bytes("ffff".as_bytes(), 16u), Some(65535u as u16));
+        assert_eq!(parse_bytes("z".as_bytes(), 36u), Some(35u as $T));
+
+        assert!(parse_bytes("Z".as_bytes(), 10u).is_none());
+        assert!(parse_bytes("_".as_bytes(), 2u).is_none());
     }
 
     #[test]
diff --git a/src/libstd/os.rs b/src/libstd/os.rs
index 66993fb9099..044b305a0dd 100644
--- a/src/libstd/os.rs
+++ b/src/libstd/os.rs
@@ -1448,9 +1448,9 @@ mod tests {
     use rand::RngUtil;
     use rand;
     use run;
-    use str;
     use str::StrSlice;
     use vec;
+    use vec::CopyableVector;
     use libc::consts::os::posix88::{S_IRUSR, S_IWUSR, S_IXUSR};
 
 
@@ -1684,7 +1684,7 @@ mod tests {
           };
           assert!((ostream as uint != 0u));
           let s = ~"hello";
-          let mut buf = str::to_bytes(s) + [0 as u8];
+          let mut buf = s.as_bytes_with_null().to_owned();
           do vec::as_mut_buf(buf) |b, _len| {
               assert!((libc::fwrite(b as *c_void, 1u as size_t,
                                    (s.len() + 1u) as size_t, ostream)
diff --git a/src/libstd/path.rs b/src/libstd/path.rs
index c8ffe007b90..02772604e45 100644
--- a/src/libstd/path.rs
+++ b/src/libstd/path.rs
@@ -947,7 +947,6 @@ pub mod windows {
 mod tests {
     use option::{None, Some};
     use path::{PosixPath, WindowsPath, windows};
-    use str;
 
     #[test]
     fn test_double_slash_collapsing() {
diff --git a/src/libstd/prelude.rs b/src/libstd/prelude.rs
index 476aef37093..e969c5d4e3a 100644
--- a/src/libstd/prelude.rs
+++ b/src/libstd/prelude.rs
@@ -64,7 +64,7 @@ pub use path::PosixPath;
 pub use path::WindowsPath;
 pub use ptr::RawPtr;
 pub use ascii::{Ascii, AsciiCast, OwnedAsciiCast, AsciiStr};
-pub use str::{StrVector, StrSlice, OwnedStr, StrUtil};
+pub use str::{StrVector, StrSlice, OwnedStr, StrUtil, NullTerminatedStr};
 pub use from_str::{FromStr};
 pub use to_bytes::IterBytes;
 pub use to_str::{ToStr, ToStrConsume};
diff --git a/src/libstd/rt/io/file.rs b/src/libstd/rt/io/file.rs
index 1f61cf25fbd..a99f5da032c 100644
--- a/src/libstd/rt/io/file.rs
+++ b/src/libstd/rt/io/file.rs
@@ -75,5 +75,5 @@ fn super_simple_smoke_test_lets_go_read_some_files_and_have_a_good_time() {
     let message = "it's alright. have a good time";
     let filename = &Path("test.txt");
     let mut outstream = FileStream::open(filename, Create, Read).unwrap();
-    outstream.write(message.to_bytes());
+    outstream.write(message.as_bytes());
 }
diff --git a/src/libstd/rt/io/flate.rs b/src/libstd/rt/io/flate.rs
index 0a9e0b1e38f..e57b80658ee 100644
--- a/src/libstd/rt/io/flate.rs
+++ b/src/libstd/rt/io/flate.rs
@@ -108,7 +108,7 @@ mod test {
         let mem_writer = MemWriter::new();
         let mut deflate_writer = DeflateWriter::new(mem_writer);
         let in_msg = "test";
-        let in_bytes = in_msg.to_bytes();
+        let in_bytes = in_msg.as_bytes();
         deflate_writer.write(in_bytes);
         deflate_writer.flush();
         let buf = deflate_writer.inner().inner();
diff --git a/src/libstd/run.rs b/src/libstd/run.rs
index 6b2fecc5001..b8e08ea53d4 100644
--- a/src/libstd/run.rs
+++ b/src/libstd/run.rs
@@ -741,8 +741,7 @@ fn with_envp<T>(env: Option<&[(~str, ~str)]>, cb: &fn(*mut c_void) -> T) -> T {
         let mut blk = ~[];
         for es.each |&(k, v)| {
             let kv = fmt!("%s=%s", k, v);
-            blk.push_all(str::as_bytes_slice(kv));
-            blk.push(0);
+            blk.push_all(kv.as_bytes_consume_with_nul());
         }
         blk.push(0);
         vec::as_imm_buf(blk, |p, _len|
diff --git a/src/libstd/str.rs b/src/libstd/str.rs
index 959fe199b93..20d2194de07 100644
--- a/src/libstd/str.rs
+++ b/src/libstd/str.rs
@@ -304,40 +304,6 @@ impl<'self> StrVector for &'self [&'self str] {
     }
 }
 
-/*
-Section: Transforming strings
-*/
-
-/**
- * Converts a string to a unique vector of bytes
- *
- * The result vector is not null-terminated.
- */
-pub fn to_bytes(s: &str) -> ~[u8] {
-    unsafe {
-        let mut v: ~[u8] = ::cast::transmute(s.to_owned());
-        vec::raw::set_len(&mut v, s.len());
-        v
-    }
-}
-
-/// Work with the string as a byte slice, not including trailing null.
-#[inline(always)]
-pub fn byte_slice<T>(s: &str, f: &fn(v: &[u8]) -> T) -> T {
-    do as_buf(s) |p,n| {
-        unsafe { vec::raw::buf_as_slice(p, n-1u, f) }
-    }
-}
-
-/// Work with the string as a byte slice, not including trailing null, without
-/// a callback.
-#[inline(always)]
-pub fn byte_slice_no_callback<'a>(s: &'a str) -> &'a [u8] {
-    unsafe {
-        cast::transmute(s)
-    }
-}
-
 /// Something that can be used to compare against a character
 pub trait CharEq {
     /// Determine if the splitter should split at the given character
@@ -1082,39 +1048,6 @@ static max_five_b: uint = 67108864u;
 static tag_six_b: uint = 252u;
 
 /**
- * Work with the byte buffer of a string.
- *
- * Allows for unsafe manipulation of strings, which is useful for foreign
- * interop.
- *
- * # Example
- *
- * ~~~ {.rust}
- * let i = str::as_bytes("Hello World") { |bytes| bytes.len() };
- * ~~~
- */
-#[inline]
-pub fn as_bytes<T>(s: &const ~str, f: &fn(&~[u8]) -> T) -> T {
-    unsafe {
-        let v: *~[u8] = cast::transmute(copy s);
-        f(&*v)
-    }
-}
-
-/**
- * Work with the byte buffer of a string as a byte slice.
- *
- * The byte slice does not include the null terminator.
- */
-pub fn as_bytes_slice<'a>(s: &'a str) -> &'a [u8] {
-    unsafe {
-        let (ptr, len): (*u8, uint) = ::cast::transmute(s);
-        let outgoing_tuple: (*u8, uint) = (ptr, len - 1);
-        return ::cast::transmute(outgoing_tuple);
-    }
-}
-
-/**
  * A dummy trait to hold all the utility methods that we implement on strings.
  */
 pub trait StrUtil {
@@ -1216,11 +1149,10 @@ pub fn subslice_offset(outer: &str, inner: &str) -> uint {
  * reallocating
  */
 pub fn capacity(s: &const ~str) -> uint {
-    do as_bytes(s) |buf| {
-        let vcap = vec::capacity(buf);
-        assert!(vcap > 0u);
-        vcap - 1u
-    }
+    let buf: &const ~[u8] = unsafe { cast::transmute(s) };
+    let vcap = vec::capacity(buf);
+    assert!(vcap > 0u);
+    vcap - 1u
 }
 
 /// Escape each char in `s` with char::escape_default.
@@ -1482,7 +1414,7 @@ pub trait StrSlice<'self> {
     fn char_at(&self, i: uint) -> char;
     fn char_range_at_reverse(&self, start: uint) -> CharRange;
     fn char_at_reverse(&self, i: uint) -> char;
-    fn to_bytes(&self) -> ~[u8];
+    fn as_bytes(&self) -> &'self [u8];
 
     fn find<C: CharEq>(&self, search: C) -> Option<uint>;
     fn rfind<C: CharEq>(&self, search: C) -> Option<uint>;
@@ -1545,12 +1477,12 @@ impl<'self> StrSlice<'self> for &'self str {
     /// An iterator over the bytes of `self`
     #[inline]
     fn bytes_iter(&self) -> StrBytesIterator<'self> {
-        StrBytesIterator { it: as_bytes_slice(*self).iter() }
+        StrBytesIterator { it: self.as_bytes().iter() }
     }
     /// An iterator over the bytes of `self`, in reverse order
     #[inline]
     fn bytes_rev_iter(&self) -> StrBytesRevIterator<'self> {
-        StrBytesRevIterator { it: as_bytes_slice(*self).rev_iter() }
+        StrBytesRevIterator { it: self.as_bytes().rev_iter() }
     }
 
     /// An iterator over substrings of `self`, separated by characters
@@ -1936,7 +1868,18 @@ impl<'self> StrSlice<'self> for &'self str {
         self.char_range_at_reverse(i).ch
     }
 
-    fn to_bytes(&self) -> ~[u8] { to_bytes(*self) }
+    /**
+     * Work with the byte buffer of a string as a byte slice.
+     *
+     * The byte slice does not include the null terminator.
+     */
+    fn as_bytes(&self) -> &'self [u8] {
+        unsafe {
+            let (ptr, len): (*u8, uint) = ::cast::transmute(*self);
+            let outgoing_tuple: (*u8, uint) = (ptr, len - 1);
+            ::cast::transmute(outgoing_tuple)
+        }
+    }
 
     /**
      * Returns the byte index of the first character of `self` that matches `search`
@@ -2052,6 +1995,50 @@ impl<'self> StrSlice<'self> for &'self str {
 }
 
 #[allow(missing_doc)]
+pub trait NullTerminatedStr {
+    fn as_bytes_with_null<'a>(&'a self) -> &'a [u8];
+}
+
+impl NullTerminatedStr for ~str {
+    /**
+     * Work with the byte buffer of a string as a byte slice.
+     *
+     * The byte slice does include the null terminator.
+     */
+    #[inline]
+    fn as_bytes_with_null<'a>(&'a self) -> &'a [u8] {
+        let ptr: &'a ~[u8] = unsafe { ::cast::transmute(self) };
+        let slice: &'a [u8] = *ptr;
+        slice
+    }
+}
+impl NullTerminatedStr for @str {
+    /**
+     * Work with the byte buffer of a string as a byte slice.
+     *
+     * The byte slice does include the null terminator.
+     */
+    #[inline]
+    fn as_bytes_with_null<'a>(&'a self) -> &'a [u8] {
+        let ptr: &'a ~[u8] = unsafe { ::cast::transmute(self) };
+        let slice: &'a [u8] = *ptr;
+        slice
+    }
+}
+// static strings are the only slices guaranteed to a nul-terminator
+impl NullTerminatedStr for &'static str {
+    /**
+     * Work with the byte buffer of a string as a byte slice.
+     *
+     * The byte slice does include the null terminator.
+     */
+    #[inline]
+    fn as_bytes_with_null(&self) -> &'static [u8] {
+        unsafe { ::cast::transmute(*self) }
+    }
+}
+
+#[allow(missing_doc)]
 pub trait OwnedStr {
     fn push_str_no_overallocate(&mut self, rhs: &str);
     fn push_str(&mut self, rhs: &str);
@@ -2062,6 +2049,8 @@ pub trait OwnedStr {
     fn append(&self, rhs: &str) -> ~str; // FIXME #4850: this should consume self.
     fn reserve(&mut self, n: uint);
     fn reserve_at_least(&mut self, n: uint);
+
+    fn as_bytes_with_null_consume(self) -> ~[u8];
 }
 
 impl OwnedStr for ~str {
@@ -2251,6 +2240,13 @@ impl OwnedStr for ~str {
     fn reserve_at_least(&mut self, n: uint) {
         self.reserve(uint::next_power_of_two(n + 1u) - 1u)
     }
+
+    /// Convert to a vector of bytes. This does not allocate a new
+    /// string, and includes the null terminator.
+    #[inline]
+    fn as_bytes_with_null_consume(self) -> ~[u8] {
+        unsafe { ::cast::transmute(self) }
+    }
 }
 
 impl Clone for ~str {
@@ -2336,7 +2332,7 @@ mod tests {
     use ptr;
     use str::*;
     use vec;
-    use vec::ImmutableVector;
+    use vec::{ImmutableVector, CopyableVector};
     use cmp::{TotalOrd, Less, Equal, Greater};
 
     #[test]
@@ -2953,11 +2949,69 @@ mod tests {
     }
 
     #[test]
+    fn test_as_bytes() {
+        // no null
+        let v = [
+            224, 184, 168, 224, 185, 132, 224, 184, 151, 224, 184, 162, 228,
+            184, 173, 229, 141, 142, 86, 105, 225, 187, 135, 116, 32, 78, 97,
+            109
+        ];
+        assert_eq!("".as_bytes(), &[]);
+        assert_eq!("abc".as_bytes(), &['a' as u8, 'b' as u8, 'c' as u8]);
+        assert_eq!("ศไทย中华Việt Nam".as_bytes(), v);
+    }
+
+    #[test]
+    fn test_as_bytes_with_null() {
+        // has null
+        let v = [
+            224, 184, 168, 224, 185, 132, 224, 184, 151, 224, 184, 162, 228,
+            184, 173, 229, 141, 142, 86, 105, 225, 187, 135, 116, 32, 78, 97,
+            109, 0
+        ];
+
+        assert_eq!("".as_bytes_with_null(), &[0]);
+        assert_eq!("abc".as_bytes_with_null(), &['a' as u8, 'b' as u8, 'c' as u8, 0]);
+        assert_eq!("ศไทย中华Việt Nam".as_bytes_with_null(), v);
+
+        let s1 = @"";
+        let s2 = @"abc";
+        let s3 = @"ศไทย中华Việt Nam";
+        assert_eq!(s1.as_bytes_with_null(), &[0]);
+        assert_eq!(s2.as_bytes_with_null(), &['a' as u8, 'b' as u8, 'c' as u8, 0]);
+        assert_eq!(s3.as_bytes_with_null(), v);
+
+        let s1 = ~"";
+        let s2 = ~"abc";
+        let s3 = ~"ศไทย中华Việt Nam";
+        assert_eq!(s1.as_bytes_with_null(), &[0]);
+        assert_eq!(s2.as_bytes_with_null(), &['a' as u8, 'b' as u8, 'c' as u8, 0]);
+        assert_eq!(s3.as_bytes_with_null(), v);
+    }
+
+    #[test]
+    fn test_as_bytes_with_null_consume() {
+        let s = ~"ศไทย中华Việt Nam";
+        let v = ~[
+            224, 184, 168, 224, 185, 132, 224, 184, 151, 224, 184, 162, 228,
+            184, 173, 229, 141, 142, 86, 105, 225, 187, 135, 116, 32, 78, 97,
+            109, 0
+        ];
+        assert_eq!((~"").as_bytes_with_null_consume(), ~[0]);
+        assert_eq!((~"abc").as_bytes_with_null_consume(),
+                   ~['a' as u8, 'b' as u8, 'c' as u8, 0]);
+        assert_eq!(s.as_bytes_with_null_consume(), v);
+    }
+
+    #[test]
     #[ignore(cfg(windows))]
     #[should_fail]
     fn test_as_bytes_fail() {
-        // Don't double free
-        as_bytes::<()>(&~"", |_bytes| fail!() );
+        // Don't double free. (I'm not sure if this exercises the
+        // original problem code path anymore.)
+        let s = ~"";
+        let _bytes = s.as_bytes_with_null();
+        fail!();
     }
 
     #[test]
@@ -3032,7 +3086,7 @@ mod tests {
     fn vec_str_conversions() {
         let s1: ~str = ~"All mimsy were the borogoves";
 
-        let v: ~[u8] = to_bytes(s1);
+        let v: ~[u8] = s1.as_bytes().to_owned();
         let s2: ~str = from_bytes(v);
         let mut i: uint = 0u;
         let n1: uint = s1.len();
diff --git a/src/libstd/to_bytes.rs b/src/libstd/to_bytes.rs
index 77e7583ebe5..c0c8b729f9e 100644
--- a/src/libstd/to_bytes.rs
+++ b/src/libstd/to_bytes.rs
@@ -18,7 +18,7 @@ use io;
 use io::Writer;
 use option::{None, Option, Some};
 use old_iter::BaseIter;
-use str;
+use str::StrSlice;
 
 pub type Cb<'self> = &'self fn(buf: &[u8]) -> bool;
 
@@ -239,27 +239,25 @@ impl<A:IterBytes> IterBytes for @[A] {
 impl<'self> IterBytes for &'self str {
     #[inline(always)]
     fn iter_bytes(&self, _lsb0: bool, f: Cb) -> bool {
-        do str::byte_slice(*self) |bytes| {
-            f(bytes)
-        }
+        f(self.as_bytes())
     }
 }
 
 impl IterBytes for ~str {
     #[inline(always)]
     fn iter_bytes(&self, _lsb0: bool, f: Cb) -> bool {
-        do str::byte_slice(*self) |bytes| {
-            f(bytes)
-        }
+        // this should possibly include the null terminator, but that
+        // breaks .find_equiv on hashmaps.
+        f(self.as_bytes())
     }
 }
 
 impl IterBytes for @str {
     #[inline(always)]
     fn iter_bytes(&self, _lsb0: bool, f: Cb) -> bool {
-        do str::byte_slice(*self) |bytes| {
-            f(bytes)
-        }
+        // this should possibly include the null terminator, but that
+        // breaks .find_equiv on hashmaps.
+        f(self.as_bytes())
     }
 }