DoubleEndedIterator for Args

[rust.git] / src / libstd / env.rs

diff --git a/src/libstd/env.rs b/src/libstd/env.rs
index 6956dc0d901a44a9f235546463a80eb64f522218..01bc733d440ebea415e3a15ff5af8fbdc920f46b 100644 (file)
--- a/src/libstd/env.rs
+++ b/src/libstd/env.rs
@@ -587,6 +587,13 @@ impl ExactSizeIterator for Args {
     fn len(&self) -> usize { self.inner.len() }
 }
 
+#[stable(feature = "env_iterators", since = "1.11.0")]
+impl DoubleEndedIterator for Args {
+    fn next_back(&mut self) -> Option<String> {
+        self.inner.next_back().map(|s| s.into_string().unwrap())
+    }
+}
+
 #[stable(feature = "env", since = "1.0.0")]
 impl Iterator for ArgsOs {
     type Item = OsString;
@@ -599,6 +606,10 @@ impl ExactSizeIterator for ArgsOs {
     fn len(&self) -> usize { self.inner.len() }
 }
 
+#[stable(feature = "env_iterators", since = "1.11.0")]
+impl DoubleEndedIterator for ArgsOs {
+    fn next_back(&mut self) -> Option<OsString> { self.inner.next_back() }
+}
 /// Constants associated with the current target
 #[stable(feature = "env", since = "1.0.0")]
 pub mod consts {