Move std::{reflect,repr,Poly} to a libdebug crate

This commit moves reflection (as well as the {:?} format modifier) to a new
libdebug crate, all of which is marked experimental.

This is a breaking change because it now requires the debug crate to be
explicitly linked if the :? format qualifier is used. This means that any code
using this feature will have to add `extern crate debug;` to the top of the
crate. Any code relying on reflection will also need to do this.

Closes #12019

[breaking-change]

2 files changed, 5 insertions, 4 deletions

diff --git a/src/libcore/ops.rs b/src/libcore/ops.rs
index 1eab5c04469..a3cb18a283e 100644
--- a/src/libcore/ops.rs
+++ b/src/libcore/ops.rs
@@ -27,6 +27,7 @@
  * demonstrates adding and subtracting two `Point`s.
  *
  * ```rust
+ * #[deriving(Show)]
  * struct Point {
  *     x: int,
  *     y: int
@@ -44,8 +45,8 @@
  *     }
  * }
  * fn main() {
- *     println!("{:?}", Point {x: 1, y: 0} + Point {x: 2, y: 3});
- *     println!("{:?}", Point {x: 1, y: 0} - Point {x: 2, y: 3});
+ *     println!("{}", Point {x: 1, y: 0} + Point {x: 2, y: 3});
+ *     println!("{}", Point {x: 1, y: 0} - Point {x: 2, y: 3});
  * }
  * ```
  *
diff --git a/src/libcore/slice.rs b/src/libcore/slice.rs
index 31313050165..795dd389958 100644
--- a/src/libcore/slice.rs
+++ b/src/libcore/slice.rs
@@ -419,7 +419,7 @@ pub trait ImmutableVector<'a, T> {
      * ```rust
      * let v = &[1,2,3,4];
      * for win in v.windows(2) {
-     *     println!("{:?}", win);
+     *     println!("{}", win);
      * }
      * ```
      *
@@ -444,7 +444,7 @@ pub trait ImmutableVector<'a, T> {
      * ```rust
      * let v = &[1,2,3,4,5];
      * for win in v.chunks(2) {
-     *     println!("{:?}", win);
+     *     println!("{}", win);
      * }
      * ```
      *