This commit relaxes the bound on `Result::unwrap` and `Result::unwrap_err` from
the `Display` trait to the `Debug` trait for generating an error message about
the unwrapping operation.
This commit is a breaking change and any breakage should be mitigated by
ensuring that `Debug` is implemented on the relevant type.
[breaking-change]
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 gets rid of the 'experimental' level, removes the non-staged_api
case (i.e. stability levels for out-of-tree crates), and lets the
staged_api attributes use 'unstable' and 'deprecated' lints.
This makes the transition period to the full feature staging design
a bit nicer.
This commit takes a first pass at stabilizing `std::thread`:
* It removes the `detach` method in favor of two constructors -- `spawn`
for detached threads, `scoped` for "scoped" (i.e., must-join)
threads. This addresses some of the surprise/frustrating debug
sessions with the previous API, in which `spawn` produced a guard that
on destruction joined the thread (unless `detach` was called).
The reason to have the division in part is that `Send` will soon not
imply `'static`, which means that `scoped` thread creation can take a
closure over *shared stack data* of the parent thread. On the other
hand, this means that the parent must not pop the relevant stack
frames while the child thread is running. The `JoinGuard` is used to
prevent this from happening by joining on drop (if you have not
already explicitly `join`ed.) The APIs around `scoped` are
future-proofed for the `Send` changes by taking an additional lifetime
parameter. With the current definition of `Send`, this is forced to be
`'static`, but when `Send` changes these APIs will gain their full
flexibility immediately.
Threads that are `spawn`ed, on the other hand, are detached from the
start and do not yield an RAII guard.
The hope is that, by making `scoped` an explicit opt-in with a very
suggestive name, it will be drastically less likely to be caught by a
surprising deadlock due to an implicit join at the end of a scope.
* The module itself is marked stable.
* Existing methods other than `spawn` and `scoped` are marked stable.
The migration path is:
```rust
Thread::spawn(f).detached()
```
becomes
```rust
Thread::spawn(f)
```
while
```rust
let res = Thread::spawn(f);
res.join()
```
becomes
```rust
let res = Thread::scoped(f);
res.join()
```
[breaking-change]
* The `sync` module is stable
* The `sync::mpsc` module is stable
* The `Sender::send` method is stable.
* The `Once::doit` method is now removed.
* Deprecated atomic initializers are removed.
* Renamed atomic initializers are now stable.
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 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]
