3 files changed, 12 insertions, 17 deletions
diff --git a/src/libstd/io/fs.rs b/src/libstd/io/fs.rs
index caff7d5e4c5..d49c56b4704 100644
--- a/src/libstd/io/fs.rs
+++ b/src/libstd/io/fs.rs
@@ -999,9 +999,9 @@ mod test {
             let mut read_buf = [0, .. 1028];
             let read_str = match check!(read_stream.read(read_buf)) {
                 -1|0 => fail!("shouldn't happen"),
-                n => str::from_utf8(read_buf.slice_to(n)).unwrap().to_owned()
+                n => str::from_utf8(read_buf.slice_to(n)).unwrap().to_string()
             };
-            assert_eq!(read_str, message.to_owned());
+            assert_eq!(read_str.as_slice(), message);
         }
         check!(unlink(filename));
     })
diff --git a/src/libstd/io/mod.rs b/src/libstd/io/mod.rs
index 6ac092fd8c6..0df2bb0f57c 100644
--- a/src/libstd/io/mod.rs
+++ b/src/libstd/io/mod.rs
@@ -705,9 +705,9 @@ pub trait Reader {
     /// UTF-8 bytes.
     fn read_to_string(&mut self) -> IoResult<String> {
         self.read_to_end().and_then(|s| {
-            match str::from_utf8(s.as_slice()) {
-                Some(s) => Ok(String::from_str(s)),
-                None => Err(standard_error(InvalidInput)),
+            match String::from_utf8(s) {
+                Ok(s)  => Ok(s),
+                Err(_) => Err(standard_error(InvalidInput)),
             }
         })
     }
@@ -1440,9 +1440,9 @@ pub trait Buffer: Reader {
     /// valid UTF-8 sequence of bytes.
     fn read_line(&mut self) -> IoResult<String> {
         self.read_until('\n' as u8).and_then(|line|
-            match str::from_utf8(line.as_slice()) {
-                Some(s) => Ok(String::from_str(s)),
-                None => Err(standard_error(InvalidInput)),
+            match String::from_utf8(line) {
+                Ok(s)  => Ok(s),
+                Err(_) => Err(standard_error(InvalidInput)),
             }
         )
     }
diff --git a/src/libstd/io/process.rs b/src/libstd/io/process.rs
index 07574b72645..bc0140a358c 100644
--- a/src/libstd/io/process.rs
+++ b/src/libstd/io/process.rs
@@ -813,8 +813,7 @@ mod tests {
         use os;
         let prog = pwd_cmd().spawn().unwrap();
 
-        let output = str::from_utf8(prog.wait_with_output().unwrap()
-                                        .output.as_slice()).unwrap().to_string();
+        let output = String::from_utf8(prog.wait_with_output().unwrap().output).unwrap();
         let parent_dir = os::getcwd();
         let child_dir = Path::new(output.as_slice().trim());
 
@@ -832,8 +831,7 @@ mod tests {
         let parent_dir = os::getcwd().dir_path();
         let prog = pwd_cmd().cwd(&parent_dir).spawn().unwrap();
 
-        let output = str::from_utf8(prog.wait_with_output().unwrap()
-                                        .output.as_slice()).unwrap().to_string();
+        let output = String::from_utf8(prog.wait_with_output().unwrap().output).unwrap();
         let child_dir = Path::new(output.as_slice().trim().into_string());
 
         let parent_stat = parent_dir.stat().unwrap();
@@ -867,8 +865,7 @@ mod tests {
         if running_on_valgrind() { return; }
 
         let prog = env_cmd().spawn().unwrap();
-        let output = str::from_utf8(prog.wait_with_output().unwrap()
-                                        .output.as_slice()).unwrap().to_string();
+        let output = String::from_utf8(prog.wait_with_output().unwrap().output).unwrap();
 
         let r = os::env();
         for &(ref k, ref v) in r.iter() {
@@ -884,9 +881,7 @@ mod tests {
         if running_on_valgrind() { return; }
 
         let mut prog = env_cmd().spawn().unwrap();
-        let output = str::from_utf8(prog.wait_with_output()
-                                        .unwrap().output.as_slice())
-                                   .unwrap().to_string();
+        let output = String::from_utf8(prog.wait_with_output().unwrap().output).unwrap();
 
         let r = os::env();
         for &(ref k, ref v) in r.iter() {