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, 3 insertions, 9 deletions

diff --git a/src/libstd/os.rs b/src/libstd/os.rs
index 78db6c158a8..985a8cd32e2 100644
--- a/src/libstd/os.rs
+++ b/src/libstd/os.rs
@@ -855,7 +855,7 @@ pub enum MapOption {
 impl Copy for MapOption {}
 
 /// Possible errors when creating a map.
-#[derive(Copy)]
+#[derive(Copy, Show)]
 pub enum MapError {
     /// # The following are POSIX-specific
     ///
@@ -900,7 +900,8 @@ pub enum MapError {
     ErrMapViewOfFile(uint)
 }
 
-impl fmt::Show for MapError {
+#[stable]
+impl fmt::Display for MapError {
     fn fmt(&self, out: &mut fmt::Formatter) -> fmt::Result {
         let str = match *self {
             ErrFdNotAvail => "fd not available for reading or writing",
@@ -934,13 +935,6 @@ impl fmt::Show for MapError {
 
 impl Error for MapError {
     fn description(&self) -> &str { "memory map error" }
-    fn detail(&self) -> Option<String> { Some(format!("{:?}", self)) }
-}
-
-impl FromError<MapError> for Box<Error + Send> {
-    fn from_error(err: MapError) -> Box<Error + Send> {
-        box err
-    }
 }
 
 // Round up `from` to be divisible by `to`