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
This commit is contained in:
Alex Crichton 2015-01-20 15:45:07 -08:00
parent 29bd9a06ef
commit 3cb9fa26ef
136 changed files with 763 additions and 706 deletions

View file

@ -133,7 +133,6 @@ impl<T> ToOwned<T> for T where T: Clone {
/// }
/// }
/// ```
#[derive(Show)]
pub enum Cow<'a, T, B: ?Sized + 'a> where B: ToOwned<T> {
/// Borrowed data.
Borrowed(&'a B),
@ -239,14 +238,27 @@ impl<'a, T, B: ?Sized> PartialOrd for Cow<'a, T, B> where B: PartialOrd + ToOwne
}
#[stable]
impl<'a, T, B: ?Sized> fmt::String for Cow<'a, T, B> where
B: fmt::String + ToOwned<T>,
T: fmt::String,
impl<'a, T, B: ?Sized> fmt::Debug for Cow<'a, T, B> where
B: fmt::Debug + ToOwned<T>,
T: fmt::Debug,
{
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
match *self {
Borrowed(ref b) => fmt::String::fmt(b, f),
Owned(ref o) => fmt::String::fmt(o, f),
Borrowed(ref b) => fmt::Debug::fmt(b, f),
Owned(ref o) => fmt::Debug::fmt(o, f),
}
}
}
#[stable]
impl<'a, T, B: ?Sized> fmt::Display for Cow<'a, T, B> where
B: fmt::Display + ToOwned<T>,
T: fmt::Display,
{
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
match *self {
Borrowed(ref b) => fmt::Display::fmt(b, f),
Owned(ref o) => fmt::Display::fmt(o, f),
}
}
}