std: Rename Show/String to Debug/Display

This commit is an implementation of [RFC 565][rfc] which is a stabilization of
the `std::fmt` module and the implementations of various formatting traits.
Specifically, the following changes were performed:

[rfc]: https://github.com/rust-lang/rfcs/blob/master/text/0565-show-string-guidelines.md

* The `Show` trait is now deprecated, it was renamed to `Debug`
* The `String` trait is now deprecated, it was renamed to `Display`
* Many `Debug` and `Display` implementations were audited in accordance with the
  RFC and audited implementations now have the `#[stable]` attribute
  * Integers and floats no longer print a suffix
  * Smart pointers no longer print details that they are a smart pointer
  * Paths with `Debug` are now quoted and escape characters
* The `unwrap` methods on `Result` now require `Display` instead of `Debug`
* The `Error` trait no longer has a `detail` method and now requires that
  `Display` must be implemented. With the loss of `String`, this has moved into
  libcore.
* `impl<E: Error> FromError<E> for Box<Error>` now exists
* `derive(Show)` has been renamed to `derive(Debug)`. This is not currently
  warned about due to warnings being emitted on stage1+

While backwards compatibility is attempted to be maintained with a blanket
implementation of `Display` for the old `String` trait (and the same for
`Show`/`Debug`) this is still a breaking change due to primitives no longer
implementing `String` as well as modifications such as `unwrap` and the `Error`
trait. Most code is fairly straightforward to update with a rename or tweaks of
method calls.

[breaking-change]
Closes #21436

1 files changed, 2 insertions, 2 deletions

diff --git a/src/libcollections/vec_map.rs b/src/libcollections/vec_map.rs
index 7ff2e953588..f178d5bc7e9 100644
--- a/src/libcollections/vec_map.rs
+++ b/src/libcollections/vec_map.rs
@@ -513,7 +513,7 @@ impl<V: Ord> Ord for VecMap<V> {
 }
 
 #[stable]
-impl<V: fmt::Show> fmt::Show for VecMap<V> {
+impl<V: fmt::Debug> fmt::Debug for VecMap<V> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         try!(write!(f, "VecMap {{"));
 
@@ -990,7 +990,7 @@ mod test_map {
         map.insert(3, 4i);
 
         let map_str = format!("{:?}", map);
-        assert!(map_str == "VecMap {1: 2i, 3: 4i}" || map_str == "{3: 4i, 1: 2i}");
+        assert!(map_str == "VecMap {1: 2, 3: 4}" || map_str == "{3: 4, 1: 2}");
         assert_eq!(format!("{:?}", empty), "VecMap {}");
     }