There's been some debate over the precise form that these APIs should take, and
they've undergone some changes recently, so these APIs are going to be left
unstable for now to be fleshed out during the next release cycle.
fmt::Show is for debugging, and can and should be implemented for
all public types. This trait is used with `{:?}` syntax. There still
exists #[derive(Show)].
fmt::String is for types that faithfully be represented as a String.
Because of this, there is no way to derive fmt::String, all
implementations must be purposeful. It is used by the default format
syntax, `{}`.
This will break most instances of `{}`, since that now requires the type
to impl fmt::String. In most cases, replacing `{}` with `{:?}` is the
correct fix. Types that were being printed specifically for users should
receive a fmt::String implementation to fix this.
Part of #20013
[breaking-change]
There's been some debate over the precise form that these APIs should take, and
they've undergone some changes recently, so these APIs are going to be left
unstable for now to be fleshed out during the next release cycle.
This removes a large array of deprecated functionality, regardless of how
recently it was deprecated. The purpose of this commit is to clean out the
standard libraries and compiler for the upcoming alpha release.
Some notable compiler changes were to enable warnings for all now-deprecated
command line arguments (previously the deprecated versions were silently
accepted) as well as removing deriving(Zero) entirely (the trait was removed).
The distribution no longer contains the libtime or libregex_macros crates. Both
of these have been deprecated for some time and are available externally.
This commit is an implementation of [RFC 503][rfc] which is a stabilization
story for the prelude. Most of the RFC was directly applied, removing reexports.
Some reexports are kept around, however:
* `range` remains until range syntax has landed to reduce churn.
* `Path` and `GenericPath` remain until path reform lands. This is done to
prevent many imports of `GenericPath` which will soon be removed.
* All `io` traits remain until I/O reform lands so imports can be rewritten all
at once to `std::io::prelude::*`.
This is a breaking change because many prelude reexports have been removed, and
the RFC can be consulted for the exact list of removed reexports, as well as to
find the locations of where to import them.
[rfc]: https://github.com/rust-lang/rfcs/blob/master/text/0503-prelude-stabilization.md
[breaking-change]
Closes#20068
This patch marks `PartialEq`, `Eq`, `PartialOrd`, and `Ord` as
`#[stable]`, as well as the majorify of manual implementaitons of these
traits. The traits match the [reform
RFC](https://github.com/rust-lang/rfcs/pull/439).
Along the way, two changes are made:
* The recently-added type parameters for `Ord` and `Eq` are
removed. These were mistakenly added while adding them to `PartialOrd`
and `PartialEq`, but they don't make sense given the laws that are
required for (and use cases for) `Ord` and `Eq`.
* More explicit laws are added for `PartialEq` and `PartialOrd`,
connecting them to their associated mathematical concepts.
In the future, many of the impls should be generalized; see
since generalizing later is not a breaking change.
[breaking-change]
This commit is a second pass stabilization for the `std::comm` module,
performing the following actions:
* The entire `std::comm` module was moved under `std::sync::mpsc`. This movement
reflects that channels are just yet another synchronization primitive, and
they don't necessarily deserve a special place outside of the other
concurrency primitives that the standard library offers.
* The `send` and `recv` methods have all been removed.
* The `send_opt` and `recv_opt` methods have been renamed to `send` and `recv`.
This means that all send/receive operations return a `Result` now indicating
whether the operation was successful or not.
* The error type of `send` is now a `SendError` to implement a custom error
message and allow for `unwrap()`. The error type contains an `into_inner`
method to extract the value.
* The error type of `recv` is now `RecvError` for the same reasons as `send`.
* The `TryRecvError` and `TrySendError` types have had public reexports removed
of their variants and the variant names have been tweaked with enum
namespacing rules.
* The `Messages` iterator is renamed to `Iter`
This functionality is now all `#[stable]`:
* `Sender`
* `SyncSender`
* `Receiver`
* `std::sync::mpsc`
* `channel`
* `sync_channel`
* `Iter`
* `Sender::send`
* `Sender::clone`
* `SyncSender::send`
* `SyncSender::try_send`
* `SyncSender::clone`
* `Receiver::recv`
* `Receiver::try_recv`
* `Receiver::iter`
* `SendError`
* `RecvError`
* `TrySendError::{mod, Full, Disconnected}`
* `TryRecvError::{mod, Empty, Disconnected}`
* `SendError::into_inner`
* `TrySendError::into_inner`
This is a breaking change due to the modification of where this module is
located, as well as the changing of the semantics of `send` and `recv`. Most
programs just need to rename imports of `std::comm` to `std::sync::mpsc` and
add calls to `unwrap` after a send or a receive operation.
[breaking-change]
This commit is an implementation of [RFC 503][rfc] which is a stabilization
story for the prelude. Most of the RFC was directly applied, removing reexports.
Some reexports are kept around, however:
* `range` remains until range syntax has landed to reduce churn.
* `Path` and `GenericPath` remain until path reform lands. This is done to
prevent many imports of `GenericPath` which will soon be removed.
* All `io` traits remain until I/O reform lands so imports can be rewritten all
at once to `std::io::prelude::*`.
This is a breaking change because many prelude reexports have been removed, and
the RFC can be consulted for the exact list of removed reexports, as well as to
find the locations of where to import them.
[rfc]: https://github.com/rust-lang/rfcs/blob/master/text/0503-prelude-stabilization.md
[breaking-change]
Closes#20068
The example derived Hash + Eq on a type that was used as *values* for
a hashmap.. for the example to make sense, we have to use a custom *key*
type.
Write a slightly more involved example, still using Vikings, but this
time as key.
I preferred using String over &str here, since that's the typical usage
and we might want to lead users down that path.
post-unboxed-closure-conversion. This requires a fair amount of
annoying coercions because all the `map` etc types are defined
generically over the `F`, so the automatic coercions don't propagate;
this is compounded by the need to use `let` and not `as` due to
stage0. That said, this pattern is to a large extent temporary and
unusual.
It is useful to move all the elements out of a hashmap without deallocating
the underlying buffer. It came up in IRC, and this patch implements it as
`drain`.
r? @Gankro
cc: @frankmcsherry
It is useful to move all the elements out of some collections without
deallocating the underlying buffer. It came up in IRC, and this patch
implements it as `drain`. This has been discussed as part of RFC 509.
r? @Gankro
cc: @frankmcsherry
followed by a semicolon.
This allows code like `vec![1i, 2, 3].len();` to work.
This breaks code that uses macros as statements without putting
semicolons after them, such as:
fn main() {
...
assert!(a == b)
assert!(c == d)
println(...);
}
It also breaks code that uses macros as items without semicolons:
local_data_key!(foo)
fn main() {
println("hello world")
}
Add semicolons to fix this code. Those two examples can be fixed as
follows:
fn main() {
...
assert!(a == b);
assert!(c == d);
println(...);
}
local_data_key!(foo);
fn main() {
println("hello world")
}
RFC #378.
Closes#18635.
[breaking-change]
This commit performs a second pass stabilization of the `std::default` module.
The module was already marked `#[stable]`, and the inheritance of `#[stable]`
was removed since this attribute was applied. This commit adds the `#[stable]`
attribute to the trait definition and one method name, along with all
implementations found in the standard distribution.
Using a type alias for iterator implementations is fragile since this
exposes the implementation to users of the iterator, and any changes
could break existing code.
This commit changes the keys and values iterators of `HashMap` to use
proper new types, rather than type aliases. However, since it is
fair-game to treat a type-alias as the aliased type, this is a:
[breaking-change].
Now that we have an overloaded comparison (`==`) operator, and that `Vec`/`String` deref to `[T]`/`str` on method calls, many `as_slice()`/`as_mut_slice()`/`to_string()` calls have become redundant. This patch removes them. These were the most common patterns:
- `assert_eq(test_output.as_slice(), "ground truth")` -> `assert_eq(test_output, "ground truth")`
- `assert_eq(test_output, "ground truth".to_string())` -> `assert_eq(test_output, "ground truth")`
- `vec.as_mut_slice().sort()` -> `vec.sort()`
- `vec.as_slice().slice(from, to)` -> `vec.slice(from_to)`
---
Note that e.g. `a_string.push_str(b_string.as_slice())` has been left untouched in this PR, since we first need to settle down whether we want to favor the `&*b_string` or the `b_string[]` notation.
This is rebased on top of #19167
cc @alexcrichton @aturon
In regards to:
https://github.com/rust-lang/rust/issues/19253#issuecomment-64836729
This commit:
* Changes the #deriving code so that it generates code that utilizes fewer
reexports (in particur Option::* and Result::*), which is necessary to
remove those reexports in the future
* Changes other areas of the codebase so that fewer reexports are utilized
Comparison traits have gained an `Rhs` input parameter that defaults to `Self`. And now the comparison operators can be overloaded to work between different types. In particular, this PR allows the following operations (and their commutative versions):
- `&str` == `String` == `CowString`
- `&[A]` == `&mut [B]` == `Vec<C>` == `CowVec<D>` == `[E, ..N]` (for `N` up to 32)
- `&mut A` == `&B` (for `Sized` `A` and `B`)
Where `A`, `B`, `C`, `D`, `E` may be different types that implement `PartialEq`. For example, these comparisons are now valid: `string == "foo"`, and `vec_of_strings == ["Hello", "world"]`.
[breaking-change]s
Since the `==` may now work on different types, operations that relied on the old "same type restriction" to drive type inference, will need to be type annotated. These are the most common fallout cases:
- `some_vec == some_iter.collect()`: `collect` needs to be type annotated: `collect::<Vec<_>>()`
- `slice == &[a, b, c]`: RHS doesn't get coerced to an slice, use an array instead `[a, b, c]`
- `lhs == []`: Change expression to `lhs.is_empty()`
- `lhs == some_generic_function()`: Type annotate the RHS as necessary
cc #19148
r? @aturon
This commit removes the `std::local_data` module in favor of a new
`std::thread_local` module providing thread local storage. The module provides
two variants of TLS: one which owns its contents and one which is based on
scoped references. Each implementation has pros and cons listed in the
documentation.
Both flavors have accessors through a function called `with` which yield a
reference to a closure provided. Both flavors also panic if a reference cannot
be yielded and provide a function to test whether an access would panic or not.
This is an implementation of [RFC 461][rfc] and full details can be found in
that RFC.
This is a breaking change due to the removal of the `std::local_data` module.
All users can migrate to the new thread local system like so:
thread_local!(static FOO: Rc<RefCell<Option<T>>> = Rc::new(RefCell::new(None)))
The old `local_data` module inherently contained the `Rc<RefCell<Option<T>>>` as
an implementation detail which must now be explicitly stated by users.
[rfc]: https://github.com/rust-lang/rfcs/pull/461
[breaking-change]
This commit deprecates the `_equiv` family of methods on `HashMap` and
`HashSet` by instead generalizing the "normal" methods like `get` and
`remove` to use the new `std::borrow` infrastructure.
[breaking-change]
This breaks code that referred to variant names in the same namespace as
their enum. Reexport the variants in the old location or alter code to
refer to the new locations:
```
pub enum Foo {
A,
B
}
fn main() {
let a = A;
}
```
=>
```
pub use self::Foo::{A, B};
pub enum Foo {
A,
B
}
fn main() {
let a = A;
}
```
or
```
pub enum Foo {
A,
B
}
fn main() {
let a = Foo::A;
}
```
[breaking-change]
I found some occurrences of "failure" and "fails" in the documentation. I changed them to "panics" if it means a task panic. Otherwise I left it as is, or changed it to "errors" to clearly distinguish them.
Also, I made a minor fix that is breaking the layout of a module page. "Example" is shown in an irrelevant place from the following page: http://doc.rust-lang.org/std/os/index.html
Throughout the docs, "failure" was replaced with "panics" if it means a
task panic. Otherwise, it remained as is, or changed to "errors" to
clearly differentiate it from a task panic.
* Renames/deprecates the simplest and most obvious methods
* Adds FIXME(conventions)s for outstanding work
* Marks "handled" methods as unstable
NOTE: the semantics of reserve and reserve_exact have changed!
Other methods have had their semantics changed as well, but in a
way that should obviously not typecheck if used incorrectly.
Lots of work and breakage to come, but this handles most of the core
APIs and most eggregious breakage. Future changes should *mostly* focus on
niche collections, APIs, or simply back-compat additions.
[breaking-change]
* Moves multi-collection files into their own directory, and splits them into seperate files
* Changes exports so that each collection has its own module
* Adds underscores to public modules and filenames to match standard naming conventions
(that is, treemap::{TreeMap, TreeSet} => tree_map::TreeMap, tree_set::TreeSet)
* Renames PriorityQueue to BinaryHeap
* Renames SmallIntMap to VecMap
* Miscellanious fallout fixes
[breaking-change]
