Deprecate `str::from_utf8_owned`

Use `String::from_utf8` instead

[breaking-change]

src/compiletest/procsrv.rs

@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use std::str;
 use std::io::process::{ProcessExit, Command, Process, ProcessOutput};
 use std::dynamic_lib::DynamicLibrary;
 
@@ -25,7 +24,7 @@ fn add_target_env(cmd: &mut Command, lib_path: &str, aux_path: Option<&str>) {
     // Add the new dylib search path var
     let var = DynamicLibrary::envvar();
     let newpath = DynamicLibrary::create_path(path.as_slice());
-    let newpath = str::from_utf8(newpath.as_slice()).unwrap().to_string();
+    let newpath = String::from_utf8(newpath).unwrap();
     cmd.env(var.to_string(), newpath);
 }
 
@@ -55,8 +54,8 @@ pub fn run(lib_path: &str,
 
             Some(Result {
                 status: status,
-                out: str::from_utf8(output.as_slice()).unwrap().to_string(),
-                err: str::from_utf8(error.as_slice()).unwrap().to_string()
+                out: String::from_utf8(output).unwrap(),
+                err: String::from_utf8(error).unwrap()
             })
         },
         Err(..) => None

src/compiletest/runtest.rs

@@ -158,7 +158,7 @@ fn run_pretty_test(config: &Config, props: &TestProps, testfile: &Path) {
         match props.pp_exact { Some(_) => 1, None => 2 };
 
     let src = File::open(testfile).read_to_end().unwrap();
-    let src = str::from_utf8(src.as_slice()).unwrap().to_string();
+    let src = String::from_utf8(src.clone()).unwrap();
     let mut srcs = vec!(src);
 
     let mut round = 0;
@@ -185,10 +185,10 @@ fn run_pretty_test(config: &Config, props: &TestProps, testfile: &Path) {
         Some(ref file) => {
             let filepath = testfile.dir_path().join(file);
             let s = File::open(&filepath).read_to_end().unwrap();
-            str::from_utf8(s.as_slice()).unwrap().to_string()
-          }
-          None => { (*srcs.get(srcs.len() - 2u)).clone() }
-        };
+            String::from_utf8(s).unwrap()
+        }
+        None => { (*srcs.get(srcs.len() - 2u)).clone() }
+    };
     let mut actual = (*srcs.get(srcs.len() - 1u)).clone();
 
     if props.pp_exact.is_some() {
@@ -582,8 +582,8 @@ fn run_debuginfo_lldb_test(config: &Config, props: &TestProps, testfile: &Path)
                     process.wait_with_output().unwrap();
 
                 (status,
-                 str::from_utf8(output.as_slice()).unwrap().to_string(),
-                 str::from_utf8(error.as_slice()).unwrap().to_string())
+                 String::from_utf8(output).unwrap(),
+                 String::from_utf8(error).unwrap())
             },
             Err(e) => {
                 fatal(format!("Failed to setup Python process for \

src/libcollections/str.rs

@@ -107,6 +107,7 @@ Section: Creating a string
 /// let string = str::from_utf8_owned(hello_vec);
 /// assert_eq!(string, Ok("hello".to_string()));
 /// ```
+#[deprecated = "Replaced by `String::from_utf8`"]
 pub fn from_utf8_owned(vv: Vec<u8>) -> Result<String, Vec<u8>> {
     String::from_utf8(vv)
 }
@@ -139,9 +140,7 @@ pub fn from_byte(b: u8) -> String {
 /// assert_eq!(string.as_slice(), "b");
 /// ```
 pub fn from_char(ch: char) -> String {
-    let mut buf = String::new();
-    buf.push_char(ch);
-    buf
+    String::from_char(ch)
 }
 
 /// Convert a vector of chars to a string
@@ -2175,19 +2174,6 @@ String::from_str("\u1111\u1171\u11b6"));
         assert_eq!(from_utf8(xs), None);
     }
 
-    #[test]
-    fn test_str_from_utf8_owned() {
-        let xs = Vec::from_slice(b"hello");
-        assert_eq!(from_utf8_owned(xs), Ok(String::from_str("hello")));
-
-        let xs = Vec::from_slice("ศไทย中华Việt Nam".as_bytes());
-        assert_eq!(from_utf8_owned(xs), Ok(String::from_str("ศไทย中华Việt Nam")));
-
-        let xs = Vec::from_slice(b"hello\xFF");
-        assert_eq!(from_utf8_owned(xs),
-                   Err(Vec::from_slice(b"hello\xFF")));
-    }
-
     #[test]
     fn test_str_from_utf8_lossy() {
         let xs = b"hello";

src/libcollections/string.rs

@@ -75,6 +75,14 @@ impl String {
     ///
     /// Returns `Err` with the original vector if the vector contains invalid
     /// UTF-8.
+    ///
+    /// # Example
+    ///
+    /// ```rust
+    /// let hello_vec = vec![104, 101, 108, 108, 111];
+    /// let string = String::from_utf8(hello_vec);
+    /// assert_eq!(string, Ok("hello".to_string()));
+    /// ```
     #[inline]
     pub fn from_utf8(vec: Vec<u8>) -> Result<String, Vec<u8>> {
         if str::is_utf8(vec.as_slice()) {
@@ -391,6 +399,19 @@ mod tests {
         });
     }
 
+    #[test]
+    fn test_str_from_utf8() {
+        let xs = Vec::from_slice(b"hello");
+        assert_eq!(String::from_utf8(xs), Ok("hello".to_string()));
+
+        let xs = Vec::from_slice("ศไทย中华Việt Nam".as_bytes());
+        assert_eq!(String::from_utf8(xs), Ok("ศไทย中华Việt Nam".to_string()));
+
+        let xs = Vec::from_slice(b"hello\xFF");
+        assert_eq!(String::from_utf8(xs),
+                   Err(Vec::from_slice(b"hello\xFF")));
+    }
+
     #[test]
     fn test_push_bytes() {
         let mut s = String::from_str("ABC");

src/libdebug/repr.rs

@@ -575,7 +575,6 @@ struct P {a: int, b: f64}
 
 #[test]
 fn test_repr() {
-    use std::str;
     use std::io::stdio::println;
     use std::char::is_alphabetic;
     use std::mem::swap;
@@ -584,7 +583,7 @@ fn test_repr() {
     fn exact_test<T>(t: &T, e:&str) {
         let mut m = io::MemWriter::new();
         write_repr(&mut m as &mut io::Writer, t).unwrap();
-        let s = str::from_utf8(m.unwrap().as_slice()).unwrap().to_string();
+        let s = String::from_utf8(m.unwrap()).unwrap();
         assert_eq!(s.as_slice(), e);
     }
 

src/libregex/test/bench.rs

@@ -163,7 +163,7 @@ fn gen_text(n: uint) -> String {
             *b = '\n' as u8
         }
     }
-    str::from_utf8(bytes.as_slice()).unwrap().to_string()
+    String::from_utf8(bytes).unwrap()
 }
 
 throughput!(easy0_32, easy0(), 32)

src/librustc/back/link.rs

@@ -380,8 +380,7 @@ pub mod write {
                     sess.note(format!("{}", &cmd).as_slice());
                     let mut note = prog.error.clone();
                     note.push_all(prog.output.as_slice());
-                    sess.note(str::from_utf8(note.as_slice()).unwrap()
-                                                             .as_slice());
+                    sess.note(str::from_utf8(note.as_slice()).unwrap());
                     sess.abort_if_errors();
                 }
             },
@@ -1177,8 +1176,7 @@ fn link_natively(sess: &Session, trans: &CrateTranslation, dylib: bool,
                 sess.note(format!("{}", &cmd).as_slice());
                 let mut output = prog.error.clone();
                 output.push_all(prog.output.as_slice());
-                sess.note(str::from_utf8(output.as_slice()).unwrap()
-                                                           .as_slice());
+                sess.note(str::from_utf8(output.as_slice()).unwrap());
                 sess.abort_if_errors();
             }
         },

src/librustc/driver/mod.rs

@@ -82,8 +82,7 @@ fn run_compiler(args: &[String]) {
             let ifile = matches.free.get(0).as_slice();
             if ifile == "-" {
                 let contents = io::stdin().read_to_end().unwrap();
-                let src = str::from_utf8(contents.as_slice()).unwrap()
-                                                             .to_string();
+                let src = String::from_utf8(contents).unwrap();
                 (StrInput(src), None)
             } else {
                 (FileInput(Path::new(ifile)), Some(Path::new(ifile)))

src/librustc/metadata/encoder.rs

@@ -1922,5 +1922,5 @@ pub fn encoded_ty(tcx: &ty::ctxt, t: ty::t) -> String {
         tcx: tcx,
         abbrevs: &RefCell::new(HashMap::new())
     }, t);
-    str::from_utf8_owned(Vec::from_slice(wr.get_ref())).unwrap().to_string()
+    str::from_utf8(wr.get_ref()).unwrap().to_string()
 }

src/librustdoc/html/render.rs

@@ -460,7 +460,7 @@ fn build_index(krate: &clean::Crate, cache: &mut Cache) -> io::IoResult<String>
 
     try!(write!(&mut w, "]}};"));
 
-    Ok(str::from_utf8(w.unwrap().as_slice()).unwrap().to_string())
+    Ok(String::from_utf8(w.unwrap()).unwrap())
 }
 
 fn write_shared(cx: &Context,

src/librustdoc/lib.rs

@@ -429,7 +429,7 @@ fn json_output(krate: clean::Crate, res: Vec<plugins::PluginJson> ,
             let mut encoder = json::Encoder::new(&mut w as &mut io::Writer);
             krate.encode(&mut encoder).unwrap();
         }
-        str::from_utf8_owned(w.unwrap()).unwrap()
+        String::from_utf8(w.unwrap()).unwrap()
     };
     let crate_json = match json::from_str(crate_json_str.as_slice()) {
         Ok(j) => j,

src/libserialize/base64.rs

@@ -146,7 +146,7 @@ impl<'a> ToBase64 for &'a [u8] {
         }
 
         unsafe {
-            str::raw::from_utf8(v.as_slice()).to_string()
+            str::raw::from_utf8_owned(v)
         }
     }
 }

src/libserialize/hex.rs

@@ -45,7 +45,7 @@ impl<'a> ToHex for &'a [u8] {
         }
 
         unsafe {
-            str::raw::from_utf8(v.as_slice()).to_string()
+            str::raw::from_utf8_owned(v)
         }
     }
 }

src/libserialize/json.rs

@@ -240,7 +240,7 @@ pub fn decode<T: ::Decodable<Decoder, DecoderError>>(s: &str) -> DecodeResult<T>
 /// Shortcut function to encode a `T` into a JSON `String`
 pub fn encode<'a, T: Encodable<Encoder<'a>, io::IoError>>(object: &T) -> String {
     let buff = Encoder::buffer_encode(object);
-    str::from_utf8_owned(buff).unwrap()
+    String::from_utf8(buff).unwrap()
 }
 
 impl fmt::Show for ErrorCode {
@@ -517,8 +517,7 @@ impl<'a> ::Encoder<io::IoError> for Encoder<'a> {
             let mut check_encoder = Encoder::new(&mut buf);
             try!(f(transmute(&mut check_encoder)));
         }
-        let out = str::from_utf8_owned(buf.unwrap()).unwrap();
-        let out = out.as_slice();
+        let out = str::from_utf8(buf.get_ref()).unwrap();
         let needs_wrapping = out.char_at(0) != '"' && out.char_at_reverse(out.len()) != '"';
         if needs_wrapping { try!(write!(self.writer, "\"")); }
         try!(f(self));
@@ -762,8 +761,7 @@ impl<'a> ::Encoder<io::IoError> for PrettyEncoder<'a> {
             let mut check_encoder = PrettyEncoder::new(&mut buf);
             try!(f(transmute(&mut check_encoder)));
         }
-        let out = str::from_utf8_owned(buf.unwrap()).unwrap();
-        let out = out.as_slice();
+        let out = str::from_utf8(buf.get_ref()).unwrap();
         let needs_wrapping = out.char_at(0) != '"' && out.char_at_reverse(out.len()) != '"';
         if needs_wrapping { try!(write!(self.writer, "\"")); }
         try!(f(self));
@@ -810,7 +808,7 @@ impl Json {
     pub fn to_pretty_str(&self) -> String {
         let mut s = MemWriter::new();
         self.to_pretty_writer(&mut s as &mut io::Writer).unwrap();
-        str::from_utf8_owned(s.unwrap()).unwrap()
+        String::from_utf8(s.unwrap()).unwrap()
     }
 
      /// If the Json value is an Object, returns the value associated with the provided key.
@@ -1728,14 +1726,14 @@ impl<T: Iterator<char>> Builder<T> {
 /// Decodes a json value from an `&mut io::Reader`
 pub fn from_reader(rdr: &mut io::Reader) -> Result<Json, BuilderError> {
     let contents = match rdr.read_to_end() {
-        Ok(c) => c,
+        Ok(c)  => c,
         Err(e) => return Err(io_error_to_error(e))
     };
-    let s = match str::from_utf8_owned(contents) {
-        Ok(s) => s,
-        _ => return Err(SyntaxError(NotUtf8, 0, 0))
+    let s = match str::from_utf8(contents.as_slice()) {
+        Some(s) => s,
+        _       => return Err(SyntaxError(NotUtf8, 0, 0))
     };
-    let mut builder = Builder::new(s.as_slice().chars());
+    let mut builder = Builder::new(s.chars());
     builder.build()
 }
 

src/libstd/ascii.rs

@@ -438,7 +438,7 @@ unsafe fn str_map_bytes(string: String, map: &'static [u8]) -> String {
         *b = map[*b as uint];
     }
 
-    String::from_str(str::from_utf8(bytes.as_slice()).unwrap())
+    String::from_utf8(bytes).unwrap()
 }
 
 #[inline]

src/libstd/fmt.rs

@@ -464,7 +464,7 @@ pub use core::fmt::{secret_pointer};
 pub fn format(args: &Arguments) -> string::String{
     let mut output = io::MemWriter::new();
     let _ = write!(&mut output, "{}", args);
-    str::from_utf8(output.unwrap().as_slice()).unwrap().into_string()
+    String::from_utf8(output.unwrap()).unwrap()
 }
 
 impl<'a> Writer for Formatter<'a> {

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));
     })

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)),
             }
         )
     }

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() {

src/libstd/rt/backtrace.rs

@@ -997,7 +997,7 @@ mod test {
     macro_rules! t( ($a:expr, $b:expr) => ({
         let mut m = MemWriter::new();
         super::demangle(&mut m, $a).unwrap();
-        assert_eq!(str::from_utf8(m.unwrap().as_slice()).unwrap().to_owned(), $b.to_owned());
+        assert_eq!(String::from_utf8(m.unwrap()).unwrap(), $b.to_string());
     }) )
 
     #[test]

src/libsyntax/ext/source_util.rs

@@ -122,17 +122,17 @@ pub fn expand_include_str(cx: &mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
         }
         Ok(bytes) => bytes,
     };
-    match str::from_utf8(bytes.as_slice()) {
-        Some(src) => {
+    match String::from_utf8(bytes) {
+        Ok(src) => {
             // Add this input file to the code map to make it available as
             // dependency information
             let filename = file.display().to_string();
-            let interned = token::intern_and_get_ident(src);
-            cx.codemap().new_filemap(filename, src.to_string());
+            let interned = token::intern_and_get_ident(src.as_slice());
+            cx.codemap().new_filemap(filename, src);
 
             base::MacExpr::new(cx.expr_str(sp, interned))
         }
-        None => {
+        Err(_) => {
             cx.span_err(sp,
                         format!("{} wasn't a utf-8 file",
                                 file.display()).as_slice());

src/libsyntax/parse/lexer/comments.rs

@@ -339,7 +339,7 @@ pub fn gather_comments_and_literals(span_diagnostic: &diagnostic::SpanHandler,
                                     srdr: &mut io::Reader)
                                  -> (Vec<Comment>, Vec<Literal>) {
     let src = srdr.read_to_end().unwrap();
-    let src = str::from_utf8(src.as_slice()).unwrap().to_string();
+    let src = String::from_utf8(src).unwrap();
     let cm = CodeMap::new();
     let filemap = cm.new_filemap(path, src);
     let mut rdr = lexer::StringReader::new_raw(span_diagnostic, filemap);

src/libsyntax/print/pprust.rs

@@ -138,7 +138,7 @@ pub fn to_string(f: |&mut State| -> IoResult<()>) -> String {
         // downcasts.
         let (_, wr): (uint, Box<MemWriter>) = mem::transmute_copy(&s.s.out);
         let result =
-            str::from_utf8_owned(Vec::from_slice(wr.get_ref())).unwrap();
+            String::from_utf8(Vec::from_slice(wr.get_ref())).unwrap();
         mem::forget(wr);
         result.to_string()
     }

src/libterm/terminfo/parser/compiled.rs

@@ -214,9 +214,9 @@ pub fn parse(file: &mut io::Reader, longnames: bool)
 
     // don't read NUL
     let bytes = try!(file.read_exact(names_bytes as uint - 1));
-    let names_str = match str::from_utf8(bytes.as_slice()) {
-        Some(s) => s.to_string(),
-        None => return Err("input not utf-8".to_string()),
+    let names_str = match String::from_utf8(bytes) {
+        Ok(s)  => s,
+        Err(_) => return Err("input not utf-8".to_string()),
     };
 
     let term_names: Vec<String> = names_str.as_slice()

src/libtest/stats.rs

@@ -1030,7 +1030,7 @@ mod tests {
             use std::io::MemWriter;
             let mut m = MemWriter::new();
             write_boxplot(&mut m as &mut io::Writer, s, 30).unwrap();
-            let out = str::from_utf8(m.unwrap().as_slice()).unwrap().to_string();
+            let out = String::from_utf8(m.unwrap()).unwrap();
             assert_eq!(out, expected);
         }
 

src/libtime/lib.rs

@@ -1086,7 +1086,7 @@ pub fn strftime(format: &str, tm: &Tm) -> String {
         }
     }
 
-    str::from_utf8(buf.as_slice()).unwrap().to_string()
+    String::from_utf8(buf).unwrap()
 }
 
 #[cfg(test)]

src/libuuid/lib.rs

@@ -327,7 +327,7 @@ impl Uuid {
             *s.get_mut(i*2+0) = digit.as_bytes()[0];
             *s.get_mut(i*2+1) = digit.as_bytes()[1];
         }
-        str::from_utf8(s.as_slice()).unwrap().to_string()
+        String::from_utf8(s).unwrap()
     }
 
     /// Returns a string of hexadecimal digits, separated into groups with a hyphen.

src/test/run-pass/issue-11881.rs

@@ -14,7 +14,6 @@ use serialize::{Encodable, Encoder};
 use serialize::json;
 use serialize::ebml::writer;
 use std::io::MemWriter;
-use std::str::from_utf8_owned;
 
 #[deriving(Encodable)]
 struct Foo {