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

src/libcoretest/finally.rs

@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![allow(deprecated)]
+
 use core::finally::{try_finally, Finally};
 use std::thread::Thread;
 

src/libcoretest/fmt/num.rs

@@ -26,11 +26,11 @@ fn test_format_int() {
     assert!(format!("{}", -1i16) == "-1");
     assert!(format!("{}", -1i32) == "-1");
     assert!(format!("{}", -1i64) == "-1");
-    assert!(format!("{:?}", 1i) == "1i");
-    assert!(format!("{:?}", 1i8) == "1i8");
-    assert!(format!("{:?}", 1i16) == "1i16");
-    assert!(format!("{:?}", 1i32) == "1i32");
-    assert!(format!("{:?}", 1i64) == "1i64");
+    assert!(format!("{:?}", 1i) == "1");
+    assert!(format!("{:?}", 1i8) == "1");
+    assert!(format!("{:?}", 1i16) == "1");
+    assert!(format!("{:?}", 1i32) == "1");
+    assert!(format!("{:?}", 1i64) == "1");
     assert!(format!("{:b}", 1i) == "1");
     assert!(format!("{:b}", 1i8) == "1");
     assert!(format!("{:b}", 1i16) == "1");
@@ -57,11 +57,11 @@ fn test_format_int() {
     assert!(format!("{}", 1u16) == "1");
     assert!(format!("{}", 1u32) == "1");
     assert!(format!("{}", 1u64) == "1");
-    assert!(format!("{:?}", 1u) == "1u");
-    assert!(format!("{:?}", 1u8) == "1u8");
-    assert!(format!("{:?}", 1u16) == "1u16");
-    assert!(format!("{:?}", 1u32) == "1u32");
-    assert!(format!("{:?}", 1u64) == "1u64");
+    assert!(format!("{:?}", 1u) == "1");
+    assert!(format!("{:?}", 1u8) == "1");
+    assert!(format!("{:?}", 1u16) == "1");
+    assert!(format!("{:?}", 1u32) == "1");
+    assert!(format!("{:?}", 1u64) == "1");
     assert!(format!("{:b}", 1u) == "1");
     assert!(format!("{:b}", 1u8) == "1");
     assert!(format!("{:b}", 1u16) == "1");
@@ -94,14 +94,14 @@ fn test_format_int() {
 #[test]
 fn test_format_int_zero() {
     assert!(format!("{}", 0i) == "0");
-    assert!(format!("{:?}", 0i) == "0i");
+    assert!(format!("{:?}", 0i) == "0");
     assert!(format!("{:b}", 0i) == "0");
     assert!(format!("{:o}", 0i) == "0");
     assert!(format!("{:x}", 0i) == "0");
     assert!(format!("{:X}", 0i) == "0");
 
     assert!(format!("{}", 0u) == "0");
-    assert!(format!("{:?}", 0u) == "0u");
+    assert!(format!("{:?}", 0u) == "0");
     assert!(format!("{:b}", 0u) == "0");
     assert!(format!("{:o}", 0u) == "0");
     assert!(format!("{:x}", 0u) == "0");

src/libcoretest/num/mod.rs

@@ -9,7 +9,7 @@
 // except according to those terms.
 
 use core::cmp::PartialEq;
-use core::fmt::Show;
+use core::fmt::Debug;
 use core::num::{NumCast, cast};
 use core::ops::{Add, Sub, Mul, Div, Rem};
 use core::marker::Copy;
@@ -37,7 +37,7 @@ pub fn test_num<T>(ten: T, two: T) where
     T: PartialEq + NumCast
      + Add<Output=T> + Sub<Output=T>
      + Mul<Output=T> + Div<Output=T>
-     + Rem<Output=T> + Show
+     + Rem<Output=T> + Debug
      + Copy
 {
     assert_eq!(ten.add(two),  cast(12i).unwrap());

src/libcoretest/result.rs

@@ -14,11 +14,11 @@ pub fn op2() -> Result<int, &'static str> { Err("sadface") }
 #[test]
 pub fn test_and() {
     assert_eq!(op1().and(Ok(667i)).unwrap(), 667);
-    assert_eq!(op1().and(Err::<(), &'static str>("bad")).unwrap_err(),
+    assert_eq!(op1().and(Err::<i32, &'static str>("bad")).unwrap_err(),
                "bad");
 
     assert_eq!(op2().and(Ok(667i)).unwrap_err(), "sadface");
-    assert_eq!(op2().and(Err::<(),&'static str>("bad")).unwrap_err(),
+    assert_eq!(op2().and(Err::<i32,&'static str>("bad")).unwrap_err(),
                "sadface");
 }
 
@@ -94,7 +94,7 @@ pub fn test_fmt_default() {
     let err: Result<int, &'static str> = Err("Err");
 
     let s = format!("{:?}", ok);
-    assert_eq!(s, "Ok(100i)");
+    assert_eq!(s, "Ok(100)");
     let s = format!("{:?}", err);
     assert_eq!(s, "Err(\"Err\")");
 }

src/libcoretest/tuple.rs

@@ -60,9 +60,9 @@ fn test_tuple_cmp() {
 #[test]
 fn test_show() {
     let s = format!("{:?}", (1i,));
-    assert_eq!(s, "(1i,)");
+    assert_eq!(s, "(1,)");
     let s = format!("{:?}", (1i, true));
-    assert_eq!(s, "(1i, true)");
+    assert_eq!(s, "(1, true)");
     let s = format!("{:?}", (1i, "hi", true));
-    assert_eq!(s, "(1i, \"hi\", true)");
+    assert_eq!(s, "(1, \"hi\", true)");
 }