This commit enables implementations of IndexMut for a number of collections,
including Vec, RingBuf, SmallIntMap, TrieMap, TreeMap, and HashMap. At the same
time this deprecates the `get_mut` methods on vectors in favor of using the
indexing notation.
cc #18424
https://github.com/rust-lang/rfcs/pull/221
The current terminology of "task failure" often causes problems when
writing or speaking about code. You often want to talk about the
possibility of an operation that returns a Result "failing", but cannot
because of the ambiguity with task failure. Instead, you have to speak
of "the failing case" or "when the operation does not succeed" or other
circumlocutions.
Likewise, we use a "Failure" header in rustdoc to describe when
operations may fail the task, but it would often be helpful to separate
out a section describing the "Err-producing" case.
We have been steadily moving away from task failure and toward Result as
an error-handling mechanism, so we should optimize our terminology
accordingly: Result-producing functions should be easy to describe.
To update your code, rename any call to `fail!` to `panic!` instead.
Assuming you have not created your own macro named `panic!`, this
will work on UNIX based systems:
grep -lZR 'fail!' . | xargs -0 -l sed -i -e 's/fail!/panic!/g'
You can of course also do this by hand.
[breaking-change]
Deprecates the `find_or_*` family of "internal mutation" methods on `HashMap` in
favour of the "external mutation" Entry API as part of RFC 60. Part of #17320,
but this still needs to be done on the rest of the maps. However they don't have
any internal mutation methods defined, so they can be done without deprecating
or breaking anything. Work on `BTree` is part of the complete rewrite in #17334.
The implemented API deviates from the API described in the RFC in two key places:
* `VacantEntry.set` yields a mutable reference to the inserted element to avoid code
duplication where complex logic needs to be done *regardless* of whether the entry
was vacant or not.
* `OccupiedEntry.into_mut` was added so that it is possible to return a reference
into the map beyond the lifetime of the Entry itself, providing functional parity
to `VacantEntry.set`.
This allows the full find_or_insert functionality to be implemented using this API.
A PR will be submitted to the RFC to amend this.
[breaking-change]
type they provide an implementation for.
This breaks code like:
mod foo {
struct Foo { ... }
}
impl foo::Foo {
...
}
Change this code to:
mod foo {
struct Foo { ... }
impl Foo {
...
}
}
Additionally, if you used the I/O path extension methods `stat`,
`lstat`, `exists`, `is_file`, or `is_dir`, note that these methods have
been moved to the the `std::io::fs::PathExtensions` trait. This breaks
code like:
fn is_it_there() -> bool {
Path::new("/foo/bar/baz").exists()
}
Change this code to:
use std::io::fs::PathExtensions;
fn is_it_there() -> bool {
Path::new("/foo/bar/baz").exists()
}
Closes#17059.
RFC #155.
[breaking-change]
This can break code that looked like:
impl Foo for Box<Any> {
fn f(&self) { ... }
}
let x: Box<Any + Send> = ...;
x.f();
Change such code to:
impl Foo for Box<Any> {
fn f(&self) { ... }
}
let x: Box<Any> = ...;
x.f();
That is, upcast before calling methods.
This is a conservative solution to #5781. A more proper treatment (see
the xfail'd `trait-contravariant-self.rs`) would take variance into
account. This change fixes the soundness hole.
Some library changes had to be made to make this work. In particular,
`Box<Any>` is no longer showable, and only `Box<Any+Send>` is showable.
Eventually, this restriction can be lifted; for now, it does not prove
too onerous, because `Any` is only used for propagating the result of
task failure.
This patch also adds a test for the variance inference work in #12828,
which accidentally landed as part of DST.
Closes#5781.
[breaking-change]
This breaks a fair amount of code. The typical patterns are:
* `for _ in range(0, 10)`: change to `for _ in range(0u, 10)`;
* `println!("{}", 3)`: change to `println!("{}", 3i)`;
* `[1, 2, 3].len()`: change to `[1i, 2, 3].len()`.
RFC #30. Closes#6023.
[breaking-change]
This creates a stability baseline for all crates that we distribute that are not `std`. In general, all library code must start as experimental and progress in stages to become stable.
This obsoletes the old `to_err_msg` method. Replace
println!("Error: {}", failure.to_err_msg())
let string = failure.to_err_msg();
with
println!("Error: {}", failure)
let string = failure.to_str();
[breaking-change]
* The select/plural methods from format strings are removed
* The # character no longer needs to be escaped
* The \-based escapes have been removed
* '{{' is now an escape for '{'
* '}}' is now an escape for '}'
Closes#14810
[breaking-change]
* The select/plural methods from format strings are removed
* The # character no longer needs to be escaped
* The \-based escapes have been removed
* '{{' is now an escape for '{'
* '}}' is now an escape for '}'
Closes#14810
[breaking-change]
The following features have been removed
* box [a, b, c]
* ~[a, b, c]
* box [a, ..N]
* ~[a, ..N]
* ~[T] (as a type)
* deprecated_owned_vector lint
All users of ~[T] should move to using Vec<T> instead.
