Add #[must_use] to non-mutating verb methods

[rust.git] / library / std / src / path.rs

diff --git a/library/std/src/path.rs b/library/std/src/path.rs
index a45ecf6ea8c63ed05ee1ff29482d6546b5fc98dd..008baa2443f50a7d59b0c46bfbf42d9458e2f1dc 100644 (file)
--- a/library/std/src/path.rs
+++ b/library/std/src/path.rs
@@ -532,6 +532,7 @@ impl<'a> Component<'a> {
     /// let components: Vec<_> = path.components().map(|comp| comp.as_os_str()).collect();
     /// assert_eq!(&components, &[".", "tmp", "foo", "bar.txt"]);
     /// ```
+    #[must_use = "`self` will be dropped if the result is not used"]
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn as_os_str(self) -> &'a OsStr {
         match self {
@@ -1145,6 +1146,7 @@ fn as_mut_vec(&mut self) -> &mut Vec<u8> {
     /// let path = PathBuf::new();
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[must_use]
     #[inline]
     pub fn new() -> PathBuf {
         PathBuf { inner: OsString::new() }
@@ -1169,6 +1171,7 @@ pub fn new() -> PathBuf {
     ///
     /// [`with_capacity`]: OsString::with_capacity
     #[stable(feature = "path_buf_capacity", since = "1.44.0")]
+    #[must_use]
     #[inline]
     pub fn with_capacity(capacity: usize) -> PathBuf {
         PathBuf { inner: OsString::with_capacity(capacity) }
@@ -1428,6 +1431,7 @@ fn _set_extension(&mut self, extension: &OsStr) -> bool {
     /// let os_str = p.into_os_string();
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[must_use = "`self` will be dropped if the result is not used"]
     #[inline]
     pub fn into_os_string(self) -> OsString {
         self.inner
@@ -1435,6 +1439,7 @@ pub fn into_os_string(self) -> OsString {
 
     /// Converts this `PathBuf` into a [boxed](Box) [`Path`].
     #[stable(feature = "into_boxed_path", since = "1.20.0")]
+    #[must_use = "`self` will be dropped if the result is not used"]
     #[inline]
     pub fn into_boxed_path(self) -> Box<Path> {
         let rw = Box::into_raw(self.inner.into_boxed_os_str()) as *mut Path;
@@ -2506,6 +2511,8 @@ pub fn iter(&self) -> Iter<'_> {
     /// println!("{}", path.display());
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[must_use = "this does not display the path, \
+                  it returns an object that can be displayed"]
     #[inline]
     pub fn display(&self) -> Display<'_> {
         Display { path: self }