This commit performs a second pass over the `std::string` module, performing the
following actions:
* The name `std::string` is now stable.
* The `String::from_utf8` function is now stable after having been altered to
return a new `FromUtf8Error` structure. The `FromUtf8Error` structure is now
stable as well as its `into_bytes` and `utf8_error` methods.
* The `String::from_utf8_lossy` function is now stable.
* The `String::from_chars` method is now deprecated in favor of `.collect()`
* The `String::from_raw_parts` method is now stable
* The `String::from_str` function remains experimental
* The `String::from_raw_buf` function remains experimental
* The `String::from_raw_buf_len` function remains experimental
* The `String::from_utf8_unchecked` function is now stable
* The `String::from_char` function is now deprecated in favor of
`repeat(c).take(n).collect()`
* The `String::grow` function is now deprecated in favor of
`.extend(repeat(c).take(n)`
* The `String::capacity` method is now stable
* The `String::reserve` method is now stable
* The `String::reserve_exact` method is now stable
* The `String::shrink_to_fit` method is now stable
* The `String::pop` method is now stable
* The `String::as_mut_vec` method is now stable
* The `String::is_empty` method is now stable
* The `IntoString` trait is now deprecated (there are no implementors)
* The `String::truncate` method is now stable
* The `String::insert` method is now stable
* The `String::remove` method is now stable
* The `String::push` method is now stable
* The `String::push_str` method is now stable
* The `String::from_utf16` function is now stable after its error type has now
become an opaque structure to carry more semantic information in the future.
A number of these changes are breaking changes, but the migrations should be
fairly straightforward on a case-by-case basis (outlined above where possible).
[breaking-change]
These crates are all deprecated for their rust-lang/$crate equivalents and by
generating docs we're generating broken links. The documentation for these
crates are generated out-of-tree and are managed separately, so we're not losing
the documentation altogether, just the links from the main distribution's docs.
Closes#20096
This stabilizes most methods on `&str` working with patterns in a way that is forwards-compatible with a generic string pattern matching API:
- Methods that are using the primary name for their operation are marked as `#[stable]`, as they can be upgraded to a full `Pattern` API later without existing code breaking. Example: `contains(&str)`
- Methods that are using a more specific name in order to not clash with the primary one are marked as `#[unstable]`, as they will likely be removed once their functionality is merged into the primary one. Example: `contains_char<C: CharEq>(C)`
- The method docs got changed to consistently refer to the pattern types as a pattern.
- Methods whose names do not match in the context of the more generic API got renamed. Example: `trim_chars -> trim_matches`
Additionally, all methods returning iterators got changed to return unique new types with changed names in accordance with the new naming guidelines.
See also https://github.com/rust-lang/rfcs/pull/528
Due to some deprecations and type changes, this is a
[breaking-change]
All of the current std::sync primitives have poisoning enable which means that
when a task fails inside of a write-access lock then all future attempts to
acquire the lock will fail. This strategy ensures that stale data whose
invariants are possibly not upheld are never viewed by other tasks to help
propagate unexpected panics (bugs in a program) among tasks.
Currently there is no way to test whether a mutex or rwlock is poisoned. One
method would be to duplicate all the methods with a sister foo_catch function,
for example. This pattern is, however, against our [error guidelines][errors].
As a result, this commit exposes the fact that a task has failed internally
through the return value of a `Result`.
[errors]: https://github.com/rust-lang/rfcs/blob/master/text/0236-error-conventions.md#do-not-provide-both-result-and-fail-variants
All methods now return a `LockResult<T>` or a `TryLockResult<T>` which
communicates whether the lock was poisoned or not. In a `LockResult`, both the
`Ok` and `Err` variants contains the `MutexGuard<T>` that is being returned in
order to allow access to the data if poisoning is not desired. This also means
that the lock is *always* held upon returning from `.lock()`.
A new type, `PoisonError`, was added with one method `into_guard` which can
consume the assertion that a lock is poisoned to gain access to the underlying
data.
This is a breaking change because the signatures of these methods have changed,
often incompatible ways. One major difference is that the `wait` methods on a
condition variable now consume the guard and return it in as a `LockResult` to
indicate whether the lock was poisoned while waiting. Most code can be updated
by calling `.unwrap()` on the return value of `.lock()`.
[breaking-change]
This takes building `librustc/lib.rs` from using 696 MB to 588 (`rustc --no-trans`), and 1.99 GB to 1.87 (`rustc -O`). It also reduces `sty` down to 32 bytes on platforms with 64-bit pointers, at the expense of some more side-tables in `ctxt`. I'm sure there's more gains to be had from reducing the size of the side tables (e.g. by making the actual things they're storing smaller).
r? @nikomatsakis
This cuts memory use dramatically from the previous commit, and reduces
use overall. E.g. the memory usage of `rustc -O librustc/lib.rs` seems
to drop 100MB from 1.98GB to 1.88GB (on one run anyway).
This extends the nullable enum opt to traverse beyond just the first level to find possible fields to use as the discriminant. So now, it'll work through structs, tuples, and fixed sized arrays. This also introduces a new lang item, NonZero, that you can use to wrap raw pointers or integral types to indicate to rustc that the underlying value is known to never be 0/NULL. We then use this in Vec, Rc and Arc to have them also benefit from the nullable enum opt.
As per https://github.com/rust-lang/rfcs/pull/499 NonZero is not exposed via the `libstd` facade.
```
x86_64 Linux:
T Option<T> (Before) Option<T> (After)
----------------------------------------------------------------------------------
Vec<int> 24 32 24
String 24 32 24
Rc<int> 8 16 8
Arc<int> 8 16 8
[Box<int>, ..2] 16 24 16
(String, uint) 32 40 32
```
Fixes#19419.
Fixes#13194.
Fixes#9378.
Fixes#7576.
Using the current directory may not always be appropriate, for example in
the case where it will unnecessarily trigger a backup to be made.
The only risk with this change is that systems might not have a mktemp.
I am not aware of such a system, but have not tested on Windows. It is
working on a basic Ubuntu and OS X installation.
[breaking-change]
This and the other commit in this PR change the rules for shadowing and globs to be
stricter. There were previously bugs where some glob imports would not be checked
for shadowing. Those are now fixed and you may have to adjust your imports to use
fewer globs.
