From 02d976a7f9ae838901b50b64109d90d54619fe4d Mon Sep 17 00:00:00 2001
From: Daniel Micay <danielmicay@gmail.com>
Date: Fri, 10 Oct 2014 06:19:40 -0400
Subject: [PATCH] improve the performance of the vec![] macro

Closes #17865
---
 src/libcollections/slice.rs |  2 +-
 src/libcollections/vec.rs   |  2 +-
 src/libstd/io/net/tcp.rs    |  1 -
 src/libstd/lib.rs           |  6 ++++--
 src/libstd/macros.rs        | 16 +++++++---------
 5 files changed, 13 insertions(+), 14 deletions(-)

diff --git a/src/libcollections/slice.rs b/src/libcollections/slice.rs
index 138bc63737e..955a1a5068b 100644
--- a/src/libcollections/slice.rs
+++ b/src/libcollections/slice.rs
@@ -2331,7 +2331,7 @@ mod tests {
     fn test_into_vec() {
         let xs = box [1u, 2, 3];
         let ys = xs.into_vec();
-        assert_eq!(ys.as_slice(), [1u, 2, 3]);
+        assert_eq!(ys.as_slice(), [1u, 2, 3].as_slice());
     }
 }
 
diff --git a/src/libcollections/vec.rs b/src/libcollections/vec.rs
index d0105e3b24a..a82856c013d 100644
--- a/src/libcollections/vec.rs
+++ b/src/libcollections/vec.rs
@@ -2650,7 +2650,7 @@ mod tests {
     fn test_into_boxed_slice() {
         let xs = vec![1u, 2, 3];
         let ys = xs.into_boxed_slice();
-        assert_eq!(ys.as_slice(), [1u, 2, 3]);
+        assert_eq!(ys.as_slice(), [1u, 2, 3].as_slice());
     }
 
     #[bench]
diff --git a/src/libstd/io/net/tcp.rs b/src/libstd/io/net/tcp.rs
index cbd02abff7d..e2a850c58e4 100644
--- a/src/libstd/io/net/tcp.rs
+++ b/src/libstd/io/net/tcp.rs
@@ -18,7 +18,6 @@
 //! listener (socket server) implements the `Listener` and `Acceptor` traits.
 
 use clone::Clone;
-use collections::MutableSeq;
 use io::IoResult;
 use iter::Iterator;
 use slice::ImmutableSlice;
diff --git a/src/libstd/lib.rs b/src/libstd/lib.rs
index ca11a7c04b7..13adfeecf85 100644
--- a/src/libstd/lib.rs
+++ b/src/libstd/lib.rs
@@ -272,7 +272,9 @@ mod std {
     // The test runner calls ::std::os::args() but really wants realstd
     #[cfg(test)] pub use realstd::os as os;
     // The test runner requires std::slice::Vector, so re-export std::slice just for it.
-    #[cfg(test)] pub use slice;
+    //
+    // It is also used in vec![]
+    pub use slice;
 
-    pub use collections; // vec!() uses MutableSeq
+    pub use boxed; // used for vec![]
 }
diff --git a/src/libstd/macros.rs b/src/libstd/macros.rs
index fa356432a67..1ad3d6eed94 100644
--- a/src/libstd/macros.rs
+++ b/src/libstd/macros.rs
@@ -323,16 +323,14 @@ macro_rules! try(
 
 /// Create a `std::vec::Vec` containing the arguments.
 #[macro_export]
-macro_rules! vec(
-    ($($e:expr),*) => ({
-        // leading _ to allow empty construction without a warning.
-        let mut _temp = ::std::vec::Vec::new();
-        $(_temp.push($e);)*
-        _temp
+macro_rules! vec[
+    ($($x:expr),*) => ({
+        use std::slice::BoxedSlice;
+        let xs: ::std::boxed::Box<[_]> = box [$($x),*];
+        xs.into_vec()
     });
-    ($($e:expr),+,) => (vec!($($e),+))
-)
-
+    ($($x:expr,)*) => (vec![$($x),*])
+]
 
 /// A macro to select an event from a number of receivers.
 ///