Auto merge of rust-lang#38648 - utkarshkukreti:question-mark-in-libstd-documentation-examples, r=pnkfelix,steveklabnik,frewsxcvx

libstd: replace all `try!` with `?` in documentation examples See rust-lang#38644. For the record, I used the following Perl one-liner and then manually fixed a couple of things it got wrong: $ perl -p -i -e 's#(///.*)try!\((.*)\)#$1$2?#' src/libstd/**/*.rs

Author: bors

src/libstd/env.rs

@@ -497,7 +497,7 @@ pub fn home_dir() -> Option<PathBuf> {
 /// let mut dir = env::temp_dir();
 /// dir.push("foo.txt");
 ///
-/// let f = try!(File::create(dir));
+/// let f = File::create(dir)?;
 /// # Ok(())
 /// # }
 /// ```

src/libstd/fs.rs

@@ -42,8 +42,8 @@ use time::SystemTime;
 /// use std::io::prelude::*;
 ///
 /// # fn foo() -> std::io::Result<()> {
-/// let mut file = try!(File::create("foo.txt"));
-/// try!(file.write_all(b"Hello, world!"));
+/// let mut file = File::create("foo.txt")?;
+/// file.write_all(b"Hello, world!")?;
 /// # Ok(())
 /// # }
 /// ```
@@ -55,9 +55,9 @@ use time::SystemTime;
 /// use std::io::prelude::*;
 ///
 /// # fn foo() -> std::io::Result<()> {
-/// let mut file = try!(File::open("foo.txt"));
+/// let mut file = File::open("foo.txt")?;
 /// let mut contents = String::new();
-/// try!(file.read_to_string(&mut contents));
+/// file.read_to_string(&mut contents)?;
 /// assert_eq!(contents, "Hello, world!");
 /// # Ok(())
 /// # }
@@ -72,10 +72,10 @@ use time::SystemTime;
 /// use std::io::prelude::*;
 ///
 /// # fn foo() -> std::io::Result<()> {
-/// let file = try!(File::open("foo.txt"));
+/// let file = File::open("foo.txt")?;
 /// let mut buf_reader = BufReader::new(file);
 /// let mut contents = String::new();
-/// try!(buf_reader.read_to_string(&mut contents));
+/// buf_reader.read_to_string(&mut contents)?;
 /// assert_eq!(contents, "Hello, world!");
 /// # Ok(())
 /// # }
@@ -227,7 +227,7 @@ impl File {
  /// use std::fs::File;
  ///
  /// # fn foo() -> std::io::Result<()> {
- /// let mut f = try!(File::open("foo.txt"));
+ /// let mut f = File::open("foo.txt")?;
  /// # Ok(())
  /// # }
  /// ```
@@ -251,7 +251,7 @@ impl File {
  /// use std::fs::File;
  ///
  /// # fn foo() -> std::io::Result<()> {
- /// let mut f = try!(File::create("foo.txt"));
+ /// let mut f = File::create("foo.txt")?;
  /// # Ok(())
  /// # }
  /// ```
@@ -272,10 +272,10 @@ impl File {
  /// use std::io::prelude::*;
  ///
  /// # fn foo() -> std::io::Result<()> {
- /// let mut f = try!(File::create("foo.txt"));
- /// try!(f.write_all(b"Hello, world!"));
+ /// let mut f = File::create("foo.txt")?;
+ /// f.write_all(b"Hello, world!")?;
  ///
- /// try!(f.sync_all());
+ /// f.sync_all()?;
  /// # Ok(())
  /// # }
  /// ```
@@ -303,10 +303,10 @@ impl File {
  /// use std::io::prelude::*;
  ///
  /// # fn foo() -> std::io::Result<()> {
- /// let mut f = try!(File::create("foo.txt"));
- /// try!(f.write_all(b"Hello, world!"));
+ /// let mut f = File::create("foo.txt")?;
+ /// f.write_all(b"Hello, world!")?;
  ///
- /// try!(f.sync_data());
+ /// f.sync_data()?;
  /// # Ok(())
  /// # }
  /// ```
@@ -333,8 +333,8 @@ impl File {
  /// use std::fs::File;
  ///
  /// # fn foo() -> std::io::Result<()> {
- /// let mut f = try!(File::create("foo.txt"));
- /// try!(f.set_len(10));
+ /// let mut f = File::create("foo.txt")?;
+ /// f.set_len(10)?;
  /// # Ok(())
  /// # }
  /// ```
@@ -351,8 +351,8 @@ impl File {
  /// use std::fs::File;
  ///
  /// # fn foo() -> std::io::Result<()> {
- /// let mut f = try!(File::open("foo.txt"));
- /// let metadata = try!(f.metadata());
+ /// let mut f = File::open("foo.txt")?;
+ /// let metadata = f.metadata()?;
  /// # Ok(())
  /// # }
  /// ```
@@ -373,8 +373,8 @@ impl File {
  /// use std::fs::File;
  ///
  /// # fn foo() -> std::io::Result<()> {
- /// let mut f = try!(File::open("foo.txt"));
- /// let file_copy = try!(f.try_clone());
+ /// let mut f = File::open("foo.txt")?;
+ /// let file_copy = f.try_clone()?;
  /// # Ok(())
  /// # }
  /// ```
@@ -691,7 +691,7 @@ impl Metadata {
  /// # fn foo() -> std::io::Result<()> {
  /// use std::fs;
  ///
- /// let metadata = try!(fs::metadata("foo.txt"));
+ /// let metadata = fs::metadata("foo.txt")?;
  ///
  /// println!("{:?}", metadata.file_type());
  /// # Ok(())
@@ -710,7 +710,7 @@ impl Metadata {
  /// # fn foo() -> std::io::Result<()> {
  /// use std::fs;
  ///
- /// let metadata = try!(fs::metadata("foo.txt"));
+ /// let metadata = fs::metadata("foo.txt")?;
  ///
  /// assert!(!metadata.is_dir());
  /// # Ok(())
@@ -727,7 +727,7 @@ impl Metadata {
  /// # fn foo() -> std::io::Result<()> {
  /// use std::fs;
  ///
- /// let metadata = try!(fs::metadata("foo.txt"));
+ /// let metadata = fs::metadata("foo.txt")?;
  ///
  /// assert!(metadata.is_file());
  /// # Ok(())
@@ -744,7 +744,7 @@ impl Metadata {
  /// # fn foo() -> std::io::Result<()> {
  /// use std::fs;
  ///
- /// let metadata = try!(fs::metadata("foo.txt"));
+ /// let metadata = fs::metadata("foo.txt")?;
  ///
  /// assert_eq!(0, metadata.len());
  /// # Ok(())
@@ -761,7 +761,7 @@ impl Metadata {
  /// # fn foo() -> std::io::Result<()> {
  /// use std::fs;
  ///
- /// let metadata = try!(fs::metadata("foo.txt"));
+ /// let metadata = fs::metadata("foo.txt")?;
  ///
  /// assert!(!metadata.permissions().readonly());
  /// # Ok(())
@@ -788,7 +788,7 @@ impl Metadata {
  /// # fn foo() -> std::io::Result<()> {
  /// use std::fs;
  ///
- /// let metadata = try!(fs::metadata("foo.txt"));
+ /// let metadata = fs::metadata("foo.txt")?;
  ///
  /// if let Ok(time) = metadata.modified() {
  /// println!("{:?}", time);
@@ -823,7 +823,7 @@ impl Metadata {
  /// # fn foo() -> std::io::Result<()> {
  /// use std::fs;
  ///
- /// let metadata = try!(fs::metadata("foo.txt"));
+ /// let metadata = fs::metadata("foo.txt")?;
  ///
  /// if let Ok(time) = metadata.accessed() {
  /// println!("{:?}", time);
@@ -854,7 +854,7 @@ impl Metadata {
  /// # fn foo() -> std::io::Result<()> {
  /// use std::fs;
  ///
- /// let metadata = try!(fs::metadata("foo.txt"));
+ /// let metadata = fs::metadata("foo.txt")?;
  ///
  /// if let Ok(time) = metadata.created() {
  /// println!("{:?}", time);
@@ -898,8 +898,8 @@ impl Permissions {
  /// use std::fs::File;
  ///
  /// # fn foo() -> std::io::Result<()> {
- /// let mut f = try!(File::create("foo.txt"));
- /// let metadata = try!(f.metadata());
+ /// let mut f = File::create("foo.txt")?;
+ /// let metadata = f.metadata()?;
  ///
  /// assert_eq!(false, metadata.permissions().readonly());
  /// # Ok(())
@@ -919,8 +919,8 @@ impl Permissions {
  /// use std::fs::File;
  ///
  /// # fn foo() -> std::io::Result<()> {
- /// let f = try!(File::create("foo.txt"));
- /// let metadata = try!(f.metadata());
+ /// let f = File::create("foo.txt")?;
+ /// let metadata = f.metadata()?;
  /// let mut permissions = metadata.permissions();
  ///
  /// permissions.set_readonly(true);
@@ -948,7 +948,7 @@ impl FileType {
  /// # fn foo() -> std::io::Result<()> {
  /// use std::fs;
  ///
- /// let metadata = try!(fs::metadata("foo.txt"));
+ /// let metadata = fs::metadata("foo.txt")?;
  /// let file_type = metadata.file_type();
  ///
  /// assert_eq!(file_type.is_dir(), false);
@@ -966,7 +966,7 @@ impl FileType {
  /// # fn foo() -> std::io::Result<()> {
  /// use std::fs;
  ///
- /// let metadata = try!(fs::metadata("foo.txt"));
+ /// let metadata = fs::metadata("foo.txt")?;
  /// let file_type = metadata.file_type();
  ///
  /// assert_eq!(file_type.is_file(), true);
@@ -995,7 +995,7 @@ impl FileType {
  /// # fn foo() -> std::io::Result<()> {
  /// use std::fs;
  ///
- /// let metadata = try!(fs::symlink_metadata("foo.txt"));
+ /// let metadata = fs::symlink_metadata("foo.txt")?;
  /// let file_type = metadata.file_type();
  ///
  /// assert_eq!(file_type.is_symlink(), false);
@@ -1040,8 +1040,8 @@ impl DirEntry {
  /// ```
  /// use std::fs;
  /// # fn foo() -> std::io::Result<()> {
- /// for entry in try!(fs::read_dir(".")) {
- /// let dir = try!(entry);
+ /// for entry in fs::read_dir(".")? {
+ /// let dir = entry?;
  /// println!("{:?}", dir.path());
  /// }
  /// # Ok(())
@@ -1193,7 +1193,7 @@ impl AsInner<fs_imp::DirEntry> for DirEntry {
 /// use std::fs;
 ///
 /// # fn foo() -> std::io::Result<()> {
-/// try!(fs::remove_file("a.txt"));
+/// fs::remove_file("a.txt")?;
 /// # Ok(())
 /// # }
 /// ```
@@ -1229,7 +1229,7 @@ pub fn remove_file<P: AsRef<Path>>(path: P) -> io::Result<()> {
 /// # fn foo() -> std::io::Result<()> {
 /// use std::fs;
 ///
-/// let attr = try!(fs::metadata("/some/file/path.txt"));
+/// let attr = fs::metadata("/some/file/path.txt")?;
 /// // inspect attr ...
 /// # Ok(())
 /// # }
@@ -1262,7 +1262,7 @@ pub fn metadata<P: AsRef<Path>>(path: P) -> io::Result<Metadata> {
 /// # fn foo() -> std::io::Result<()> {
 /// use std::fs;
 ///
-/// let attr = try!(fs::symlink_metadata("/some/file/path.txt"));
+/// let attr = fs::symlink_metadata("/some/file/path.txt")?;
 /// // inspect attr ...
 /// # Ok(())
 /// # }
@@ -1305,7 +1305,7 @@ pub fn symlink_metadata<P: AsRef<Path>>(path: P) -> io::Result<Metadata> {
 /// use std::fs;
 ///
 /// # fn foo() -> std::io::Result<()> {
-/// try!(fs::rename("a.txt", "b.txt")); // Rename a.txt to b.txt
+/// fs::rename("a.txt", "b.txt")?; // Rename a.txt to b.txt
 /// # Ok(())
 /// # }
 /// ```
@@ -1349,7 +1349,7 @@ pub fn rename<P: AsRef<Path>, Q: AsRef<Path>>(from: P, to: Q) -> io::Result<()>
 /// use std::fs;
 ///
 /// # fn foo() -> std::io::Result<()> {
-/// try!(fs::copy("foo.txt", "bar.txt")); // Copy foo.txt to bar.txt
+/// fs::copy("foo.txt", "bar.txt")?; // Copy foo.txt to bar.txt
 /// # Ok(()) }
 /// ```
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -1382,7 +1382,7 @@ pub fn copy<P: AsRef<Path>, Q: AsRef<Path>>(from: P, to: Q) -> io::Result<u64> {
 /// use std::fs;
 ///
 /// # fn foo() -> std::io::Result<()> {
-/// try!(fs::hard_link("a.txt", "b.txt")); // Hard link a.txt to b.txt
+/// fs::hard_link("a.txt", "b.txt")?; // Hard link a.txt to b.txt
 /// # Ok(())
 /// # }
 /// ```
@@ -1405,7 +1405,7 @@ pub fn hard_link<P: AsRef<Path>, Q: AsRef<Path>>(src: P, dst: Q) -> io::Result<(
 /// use std::fs;
 ///
 /// # fn foo() -> std::io::Result<()> {
-/// try!(fs::soft_link("a.txt", "b.txt"));
+/// fs::soft_link("a.txt", "b.txt")?;
 /// # Ok(())
 /// # }
 /// ```
@@ -1441,7 +1441,7 @@ pub fn soft_link<P: AsRef<Path>, Q: AsRef<Path>>(src: P, dst: Q) -> io::Result<(
 /// use std::fs;
 ///
 /// # fn foo() -> std::io::Result<()> {
-/// let path = try!(fs::read_link("a.txt"));
+/// let path = fs::read_link("a.txt")?;
 /// # Ok(())
 /// # }
 /// ```
@@ -1474,7 +1474,7 @@ pub fn read_link<P: AsRef<Path>>(path: P) -> io::Result<PathBuf> {
 /// use std::fs;
 ///
 /// # fn foo() -> std::io::Result<()> {
-/// let path = try!(fs::canonicalize("../a/../foo.txt"));
+/// let path = fs::canonicalize("../a/../foo.txt")?;
 /// # Ok(())
 /// # }
 /// ```
@@ -1506,7 +1506,7 @@ pub fn canonicalize<P: AsRef<Path>>(path: P) -> io::Result<PathBuf> {
 /// use std::fs;
 ///
 /// # fn foo() -> std::io::Result<()> {
-/// try!(fs::create_dir("/some/dir"));
+/// fs::create_dir("/some/dir")?;
 /// # Ok(())
 /// # }
 /// ```
@@ -1541,7 +1541,7 @@ pub fn create_dir<P: AsRef<Path>>(path: P) -> io::Result<()> {
 /// use std::fs;
 ///
 /// # fn foo() -> std::io::Result<()> {
-/// try!(fs::create_dir_all("/some/dir"));
+/// fs::create_dir_all("/some/dir")?;
 /// # Ok(())
 /// # }
 /// ```
@@ -1573,7 +1573,7 @@ pub fn create_dir_all<P: AsRef<Path>>(path: P) -> io::Result<()> {
 /// use std::fs;
 ///
 /// # fn foo() -> std::io::Result<()> {
-/// try!(fs::remove_dir("/some/dir"));
+/// fs::remove_dir("/some/dir")?;
 /// # Ok(())
 /// # }
 /// ```
@@ -1606,7 +1606,7 @@ pub fn remove_dir<P: AsRef<Path>>(path: P) -> io::Result<()> {
 /// use std::fs;
 ///
 /// # fn foo() -> std::io::Result<()> {
-/// try!(fs::remove_dir_all("/some/dir"));
+/// fs::remove_dir_all("/some/dir")?;
 /// # Ok(())
 /// # }
 /// ```
@@ -1649,11 +1649,11 @@ pub fn remove_dir_all<P: AsRef<Path>>(path: P) -> io::Result<()> {
 /// // one possible implementation of walking a directory only visiting files
 /// fn visit_dirs(dir: &Path, cb: &Fn(&DirEntry)) -> io::Result<()> {
 /// if dir.is_dir() {
-/// for entry in try!(fs::read_dir(dir)) {
-/// let entry = try!(entry);
+/// for entry in fs::read_dir(dir)? {
+/// let entry = entry?;
 /// let path = entry.path();
 /// if path.is_dir() {
-/// try!(visit_dirs(&path, cb));
+/// visit_dirs(&path, cb)?;
 /// } else {
 /// cb(&entry);
 /// }
@@ -1690,9 +1690,9 @@ pub fn read_dir<P: AsRef<Path>>(path: P) -> io::Result<ReadDir> {
 /// # fn foo() -> std::io::Result<()> {
 /// use std::fs;
 ///
-/// let mut perms = try!(fs::metadata("foo.txt")).permissions();
+/// let mut perms = fs::metadata("foo.txt")?.permissions();
 /// perms.set_readonly(true);
-/// try!(fs::set_permissions("foo.txt", perms));
+/// fs::set_permissions("foo.txt", perms)?;
 /// # Ok(())
 /// # }
 /// ```