diff --git a/src/libextra/base64.rs b/src/libextra/base64.rs
index d6ab36ca721..b4431004bd7 100644
--- a/src/libextra/base64.rs
+++ b/src/libextra/base64.rs
@@ -150,29 +150,6 @@ impl<'self> ToBase64 for &'self [u8] {
     }
 }
 
-impl<'self> ToBase64 for &'self str {
-    /**
-     * Convert any string (literal, `@`, `&`, or `~`) to base64 encoding.
-     *
-     *
-     * # Example
-     *
-     * ~~~ {.rust}
-     * extern mod extra;
-     * use extra::base64::{ToBase64, standard};
-     *
-     * fn main () {
-     *     let str = "Hello, World".to_base64(standard);
-     *     printfln!("%s", str);
-     * }
-     * ~~~
-     *
-     */
-    fn to_base64(&self, config: Config) -> ~str {
-        self.as_bytes().to_base64(config)
-    }
-}
-
 /// A trait for converting from base64 encoded values.
 pub trait FromBase64 {
     /// Converts the value of `self`, interpreted as base64 encoded data, into
@@ -180,76 +157,6 @@ pub trait FromBase64 {
     fn from_base64(&self) -> Result<~[u8], ~str>;
 }
 
-impl<'self> FromBase64 for &'self [u8] {
-    /**
-     * Convert base64 `u8` vector into u8 byte values.
-     * Every 4 encoded characters is converted into 3 octets, modulo padding.
-     *
-     * # Example
-     *
-     * ~~~ {.rust}
-     * extern mod extra;
-     * use extra::base64::{ToBase64, FromBase64, standard};
-     *
-     * fn main () {
-     *     let str = [52,32].to_base64(standard);
-     *     printfln!("%s", str);
-     *     let bytes = str.from_base64();
-     *     printfln!("%?", bytes);
-     * }
-     * ~~~
-     */
-    fn from_base64(&self) -> Result<~[u8], ~str> {
-        let mut r = ~[];
-        let mut buf: u32 = 0;
-        let mut modulus = 0;
-
-        let mut it = self.iter();
-        for &byte in it {
-            let ch = byte as char;
-            let val = byte as u32;
-
-            match ch {
-                'A'..'Z' => buf |= val - 0x41,
-                'a'..'z' => buf |= val - 0x47,
-                '0'..'9' => buf |= val + 0x04,
-                '+'|'-' => buf |= 0x3E,
-                '/'|'_' => buf |= 0x3F,
-                '\r'|'\n' => loop,
-                '=' => break,
-                _ => return Err(~"Invalid Base64 character")
-            }
-
-            buf <<= 6;
-            modulus += 1;
-            if modulus == 4 {
-                modulus = 0;
-                r.push((buf >> 22) as u8);
-                r.push((buf >> 14) as u8);
-                r.push((buf >> 6 ) as u8);
-            }
-        }
-
-        if !it.all(|&byte| {byte as char == '='}) {
-            return Err(~"Invalid Base64 character");
-        }
-
-        match modulus {
-            2 => {
-                r.push((buf >> 10) as u8);
-            }
-            3 => {
-                r.push((buf >> 16) as u8);
-                r.push((buf >> 8 ) as u8);
-            }
-            0 => (),
-            _ => return Err(~"Invalid Base64 length")
-        }
-
-        Ok(r)
-    }
-}
-
 impl<'self> FromBase64 for &'self str {
     /**
      * Convert any base64 encoded string (literal, `@`, `&`, or `~`)
@@ -279,7 +186,56 @@ impl<'self> FromBase64 for &'self str {
      * ~~~
      */
     fn from_base64(&self) -> Result<~[u8], ~str> {
-        self.as_bytes().from_base64()
+        let mut r = ~[];
+        let mut buf: u32 = 0;
+        let mut modulus = 0;
+
+        let mut it = self.byte_iter().enumerate();
+        for (idx, byte) in it {
+            let val = byte as u32;
+
+            match byte as char {
+                'A'..'Z' => buf |= val - 0x41,
+                'a'..'z' => buf |= val - 0x47,
+                '0'..'9' => buf |= val + 0x04,
+                '+'|'-' => buf |= 0x3E,
+                '/'|'_' => buf |= 0x3F,
+                '\r'|'\n' => loop,
+                '=' => break,
+                _ => return Err(fmt!("Invalid character '%c' at position %u",
+                                     self.char_at(idx), idx))
+            }
+
+            buf <<= 6;
+            modulus += 1;
+            if modulus == 4 {
+                modulus = 0;
+                r.push((buf >> 22) as u8);
+                r.push((buf >> 14) as u8);
+                r.push((buf >> 6 ) as u8);
+            }
+        }
+
+        for (idx, byte) in it {
+            if (byte as char) != '=' {
+                return Err(fmt!("Invalid character '%c' at position %u",
+                                self.char_at(idx), idx));
+            }
+        }
+
+        match modulus {
+            2 => {
+                r.push((buf >> 10) as u8);
+            }
+            3 => {
+                r.push((buf >> 16) as u8);
+                r.push((buf >> 8 ) as u8);
+            }
+            0 => (),
+            _ => return Err(~"Invalid Base64 length")
+        }
+
+        Ok(r)
     }
 }
 
@@ -290,27 +246,28 @@ mod test {
 
     #[test]
     fn test_to_base64_basic() {
-        assert_eq!("".to_base64(STANDARD), ~"");
-        assert_eq!("f".to_base64(STANDARD), ~"Zg==");
-        assert_eq!("fo".to_base64(STANDARD), ~"Zm8=");
-        assert_eq!("foo".to_base64(STANDARD), ~"Zm9v");
-        assert_eq!("foob".to_base64(STANDARD), ~"Zm9vYg==");
-        assert_eq!("fooba".to_base64(STANDARD), ~"Zm9vYmE=");
-        assert_eq!("foobar".to_base64(STANDARD), ~"Zm9vYmFy");
+        assert_eq!("".as_bytes().to_base64(STANDARD), ~"");
+        assert_eq!("f".as_bytes().to_base64(STANDARD), ~"Zg==");
+        assert_eq!("fo".as_bytes().to_base64(STANDARD), ~"Zm8=");
+        assert_eq!("foo".as_bytes().to_base64(STANDARD), ~"Zm9v");
+        assert_eq!("foob".as_bytes().to_base64(STANDARD), ~"Zm9vYg==");
+        assert_eq!("fooba".as_bytes().to_base64(STANDARD), ~"Zm9vYmE=");
+        assert_eq!("foobar".as_bytes().to_base64(STANDARD), ~"Zm9vYmFy");
     }
 
     #[test]
     fn test_to_base64_line_break() {
         assert!(![0u8, 1000].to_base64(Config {line_length: None, ..STANDARD})
                 .contains("\r\n"));
-        assert_eq!("foobar".to_base64(Config {line_length: Some(4), ..STANDARD}),
+        assert_eq!("foobar".as_bytes().to_base64(Config {line_length: Some(4),
+                                                         ..STANDARD}),
                    ~"Zm9v\r\nYmFy");
     }
 
     #[test]
     fn test_to_base64_padding() {
-        assert_eq!("f".to_base64(Config {pad: false, ..STANDARD}), ~"Zg");
-        assert_eq!("fo".to_base64(Config {pad: false, ..STANDARD}), ~"Zm8");
+        assert_eq!("f".as_bytes().to_base64(Config {pad: false, ..STANDARD}), ~"Zg");
+        assert_eq!("fo".as_bytes().to_base64(Config {pad: false, ..STANDARD}), ~"Zm8");
     }
 
     #[test]
@@ -344,7 +301,7 @@ mod test {
     #[test]
     fn test_from_base64_invalid_char() {
         assert!("Zm$=".from_base64().is_err())
-            assert!("Zg==$".from_base64().is_err());
+        assert!("Zg==$".from_base64().is_err());
     }
 
     #[test]
@@ -368,20 +325,20 @@ mod test {
     }
 
     #[bench]
-    pub fn to_base64(bh: & mut BenchHarness) {
+    pub fn bench_to_base64(bh: & mut BenchHarness) {
         let s = "イロハニホヘト チリヌルヲ ワカヨタレソ ツネナラム \
                  ウヰノオクヤマ ケフコエテ アサキユメミシ ヱヒモセスン";
         do bh.iter {
-            s.to_base64(STANDARD);
+            s.as_bytes().to_base64(STANDARD);
         }
         bh.bytes = s.len() as u64;
     }
 
     #[bench]
-    pub fn from_base64(bh: & mut BenchHarness) {
+    pub fn bench_from_base64(bh: & mut BenchHarness) {
         let s = "イロハニホヘト チリヌルヲ ワカヨタレソ ツネナラム \
                  ウヰノオクヤマ ケフコエテ アサキユメミシ ヱヒモセスン";
-        let b = s.to_base64(STANDARD);
+        let b = s.as_bytes().to_base64(STANDARD);
         do bh.iter {
             b.from_base64();
         }
diff --git a/src/libextra/hex.rs b/src/libextra/hex.rs
index ddd1276a987..2a6a8a52055 100644
--- a/src/libextra/hex.rs
+++ b/src/libextra/hex.rs
@@ -50,29 +50,6 @@ impl<'self> ToHex for &'self [u8] {
     }
 }
 
-impl<'self> ToHex for &'self str {
-    /**
-     * Convert any string (literal, `@`, `&`, or `~`) to hexadecimal encoding.
-     *
-     *
-     * # Example
-     *
-     * ~~~ {.rust}
-     * extern mod extra;
-     * use extra::ToHex;
-     *
-     * fn main () {
-     *     let str = "Hello, World".to_hex();
-     *     printfln!("%s", str);
-     * }
-     * ~~~
-     *
-     */
-    fn to_hex(&self) -> ~str {
-        self.as_bytes().to_hex()
-    }
-}
-
 /// A trait for converting hexadecimal encoded values
 pub trait FromHex {
     /// Converts the value of `self`, interpreted as hexadecimal encoded data,
@@ -80,61 +57,6 @@ pub trait FromHex {
     fn from_hex(&self) -> Result<~[u8], ~str>;
 }
 
-impl<'self> FromHex for &'self [u8] {
-    /**
-     * Convert hexadecimal `u8` vector into u8 byte values.
-     * Every 2 encoded characters is converted into 1 octet.
-     * Whitespace is ignored.
-     *
-     * # Example
-     *
-     * ~~~ {.rust}
-     * extern mod extra;
-     * use extra::hex::{ToHex, FromHex};
-     *
-     * fn main () {
-     *     let str = [52,32].to_hex();
-     *     printfln!("%s", str);
-     *     let bytes = str.from_hex().get();
-     *     printfln!("%?", bytes);
-     * }
-     * ~~~
-     */
-    fn from_hex(&self) -> Result<~[u8], ~str> {
-        // This may be an overestimate if there is any whitespace
-        let mut b = vec::with_capacity(self.len() / 2);
-        let mut modulus = 0;
-        let mut buf = 0u8;
-
-        for (idx, &byte) in self.iter().enumerate() {
-            buf <<= 4;
-
-            match byte as char {
-                'A'..'F' => buf |= byte - ('A' as u8) + 10,
-                'a'..'f' => buf |= byte - ('a' as u8) + 10,
-                '0'..'9' => buf |= byte - ('0' as u8),
-                ' '|'\r'|'\n'|'\t' => {
-                    buf >>= 4;
-                    loop
-                }
-                _ => return Err(fmt!("Invalid byte '%c' found at position %u",
-                                     byte as char, idx))
-            }
-
-            modulus += 1;
-            if modulus == 2 {
-                modulus = 0;
-                b.push(buf);
-            }
-        }
-
-        match modulus {
-            0 => Ok(b),
-            _ => Err(~"Invalid input length")
-        }
-    }
-}
-
 impl<'self> FromHex for &'self str {
     /**
      * Convert any hexadecimal encoded string (literal, `@`, `&`, or `~`)
@@ -164,7 +86,37 @@ impl<'self> FromHex for &'self str {
      * ~~~
      */
     fn from_hex(&self) -> Result<~[u8], ~str> {
-        self.as_bytes().from_hex()
+        // This may be an overestimate if there is any whitespace
+        let mut b = vec::with_capacity(self.len() / 2);
+        let mut modulus = 0;
+        let mut buf = 0u8;
+
+        for (idx, byte) in self.byte_iter().enumerate() {
+            buf <<= 4;
+
+            match byte as char {
+                'A'..'F' => buf |= byte - ('A' as u8) + 10,
+                'a'..'f' => buf |= byte - ('a' as u8) + 10,
+                '0'..'9' => buf |= byte - ('0' as u8),
+                ' '|'\r'|'\n'|'\t' => {
+                    buf >>= 4;
+                    loop
+                }
+                _ => return Err(fmt!("Invalid character '%c' at position %u",
+                                     self.char_at(idx), idx))
+            }
+
+            modulus += 1;
+            if modulus == 2 {
+                modulus = 0;
+                b.push(buf);
+            }
+        }
+
+        match modulus {
+            0 => Ok(b),
+            _ => Err(~"Invalid input length")
+        }
     }
 }
 
@@ -175,7 +127,7 @@ mod tests {
 
     #[test]
     pub fn test_to_hex() {
-        assert_eq!("foobar".to_hex(), ~"666f6f626172");
+        assert_eq!("foobar".as_bytes().to_hex(), ~"666f6f626172");
     }
 
     #[test]
@@ -223,7 +175,7 @@ mod tests {
         let s = "イロハニホヘト チリヌルヲ ワカヨタレソ ツネナラム \
                  ウヰノオクヤマ ケフコエテ アサキユメミシ ヱヒモセスン";
         do bh.iter {
-            s.to_hex();
+            s.as_bytes().to_hex();
         }
         bh.bytes = s.len() as u64;
     }
@@ -232,7 +184,7 @@ mod tests {
     pub fn bench_from_hex(bh: & mut BenchHarness) {
         let s = "イロハニホヘト チリヌルヲ ワカヨタレソ ツネナラム \
                  ウヰノオクヤマ ケフコエテ アサキユメミシ ヱヒモセスン";
-        let b = s.to_hex();
+        let b = s.as_bytes().to_hex();
         do bh.iter {
             b.from_hex();
         }