impl<T> [T]

src/libcollections/macros.rs

@@ -8,6 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#[cfg(stage0)]
 /// Creates a `Vec` containing the arguments.
 ///
 /// `vec!` allows `Vec`s to be defined with the same syntax as array expressions.
@@ -45,6 +46,43 @@ macro_rules! vec {
     ($($x:expr,)*) => (vec![$($x),*])
 }
 
+#[cfg(not(stage0))]
+/// Creates a `Vec` containing the arguments.
+///
+/// `vec!` allows `Vec`s to be defined with the same syntax as array expressions.
+/// There are two forms of this macro:
+///
+/// - Create a `Vec` containing a given list of elements:
+///
+/// ```
+/// let v = vec![1, 2, 3];
+/// assert_eq!(v[0], 1);
+/// assert_eq!(v[1], 2);
+/// assert_eq!(v[2], 3);
+/// ```
+///
+/// - Create a `Vec` from a given element and size:
+///
+/// ```
+/// let v = vec![1; 3];
+/// assert_eq!(v, [1, 1, 1]);
+/// ```
+///
+/// Note that unlike array expressions this syntax supports all elements
+/// which implement `Clone` and the number of elements doesn't have to be
+/// a constant.
+#[macro_export]
+#[stable(feature = "rust1", since = "1.0.0")]
+macro_rules! vec {
+    ($elem:expr; $n:expr) => (
+        $crate::vec::from_elem($elem, $n)
+    );
+    ($($x:expr),*) => (
+        <[_]>::into_vec($crate::boxed::Box::new([$($x),*]))
+    );
+    ($($x:expr,)*) => (vec![$($x),*])
+}
+
 /// Use the syntax described in `std::fmt` to create a value of type `String`.
 /// See `std::fmt` for more information.
 ///