* Rename `utf16_items` to `decode_utf16`. "Items" is meaningless.
* Move it to `rustc_unicode::char`, exposed in `std::char`.
* Generalize it to any `u16` iterable, not just `&[u16]`.
* Make it yield `Result` instead of a custom `Utf16Item` enum that was isomorphic to `Result`. This enable using the `FromIterator for Result` impl.
* Add a `REPLACEMENT_CHARACTER` constant.
* Document how `result.unwrap_or(REPLACEMENT_CHARACTER)` replaces `Utf16Item::to_char_lossy`.
This PR implements the majority of RFC 1214. In particular, it implements:
- the new outlives relation
- comprehensive WF checking
For the most part, new code receives warnings, not errors, though 3 regressions were found via a crater run.
There are some deviations from RFC 1214. Most notably:
- we still consider implied bounds from fn ret; this intersects other soundness issues that I intend to address in detail in a follow-up RFC. Fixing this without breaking a lot of code probably requires rewriting compare-method somewhat (which is probably a good thing).
- object types do not check trait bounds for fear of encountering `Self`; this was left as an unresolved question in RFC 1214, but ultimately feels inconsistent.
Both of those two issues are highlighted in the tracking issue, https://github.com/rust-lang/rust/issues/27579. #27579 also includes a testing matrix with new tests that I wrote -- these probably duplicate some existing tests, I tried to check but wasn't quite sure what to look for. I tried to be thorough in testing the WF relation, at least, but would welcome suggestions for missing tests.
r? @nrc (or perhaps someone else?)
This commit removes all unstable and deprecated functions in the standard
library. A release was recently cut (1.3) which makes this a good time for some
spring cleaning of the deprecated functions.
VecMap doesn't really fit with the current standard library's strategy (small!).
I've mirrored the code to https://github.com/contain-rs/vec-map
but @GBGamer has already claimed the name on crates.io a couple months ago for the same purpose. It hasn't been updated since, though.
CC @rust-lang/libs
This commit shards the broad `core` feature of the libcore library into finer
grained features. This split groups together similar APIs and enables tracking
each API separately, giving a better sense of where each feature is within the
stabilization process.
A few minor APIs were deprecated along the way:
* Iterator::reverse_in_place
* marker::NoCopy
This commit removes all the old casting/generic traits from `std::num` that are
no longer in use by the standard library. This additionally removes the old
`strconv` module which has not seen much use in quite a long time. All generic
functionality has been supplanted with traits in the `num` crate and the
`strconv` module is supplanted with the [rust-strconv crate][rust-strconv].
[rust-strconv]: https://github.com/lifthrasiir/rust-strconv
This is a breaking change due to the removal of these deprecated crates, and the
alternative crates are listed above.
[breaking-change]
This patch
1. renames libunicode to librustc_unicode,
2. deprecates several pieces of libunicode (see below), and
3. removes references to deprecated functions from
librustc_driver and libsyntax. This may change pretty-printed
output from these modules in cases involving wide or combining
characters used in filenames, identifiers, etc.
The following functions are marked deprecated:
1. char.width() and str.width():
--> use unicode-width crate
2. str.graphemes() and str.grapheme_indices():
--> use unicode-segmentation crate
3. str.nfd_chars(), str.nfkd_chars(), str.nfc_chars(), str.nfkc_chars(),
char.compose(), char.decompose_canonical(), char.decompose_compatible(),
char.canonical_combining_class():
--> use unicode-normalization crate
This patch
1. renames libunicode to librustc_unicode,
2. deprecates several pieces of libunicode (see below), and
3. removes references to deprecated functions from
librustc_driver and libsyntax. This may change pretty-printed
output from these modules in cases involving wide or combining
characters used in filenames, identifiers, etc.
The following functions are marked deprecated:
1. char.width() and str.width():
--> use unicode-width crate
2. str.graphemes() and str.grapheme_indices():
--> use unicode-segmentation crate
3. str.nfd_chars(), str.nfkd_chars(), str.nfc_chars(), str.nfkc_chars(),
char.compose(), char.decompose_canonical(), char.decompose_compatible(),
char.canonical_combining_class():
--> use unicode-normalization crate
* Marks `#[stable]` the contents of the `std::convert` module.
* Added methods `PathBuf::as_path`, `OsString::as_os_str`,
`String::as_str`, `Vec::{as_slice, as_mut_slice}`.
* Deprecates `OsStr::from_str` in favor of a new, stable, and more
general `OsStr::new`.
* Adds unstable methods `OsString::from_bytes` and `OsStr::{to_bytes,
to_cstring}` for ergonomic FFI usage.
[breaking-change]
r? @alexcrichton
* Marks `#[stable]` the contents of the `std::convert` module.
* Added methods `PathBuf::as_path`, `OsString::as_os_str`,
`String::as_str`, `Vec::{as_slice, as_mut_slice}`.
* Deprecates `OsStr::from_str` in favor of a new, stable, and more
general `OsStr::new`.
* Adds unstable methods `OsString::from_bytes` and `OsStr::{to_bytes,
to_cstring}` for ergonomic FFI usage.
[breaking-change]
This commit stabilizes the `std::num` module:
* The `Int` and `Float` traits are deprecated in favor of (1) the
newly-added inherent methods and (2) the generic traits available in
rust-lang/num.
* The `Zero` and `One` traits are reintroduced in `std::num`, which
together with various other traits allow you to recover the most
common forms of generic programming.
* The `FromStrRadix` trait, and associated free function, is deprecated
in favor of inherent implementations.
* A wide range of methods and constants for both integers and floating
point numbers are now `#[stable]`, having been adjusted for integer
guidelines.
* `is_positive` and `is_negative` are renamed to `is_sign_positive` and
`is_sign_negative`, in order to address #22985
* The `Wrapping` type is moved to `std::num` and stabilized;
`WrappingOps` is deprecated in favor of inherent methods on the
integer types, and direct implementation of operations on
`Wrapping<X>` for each concrete integer type `X`.
Closes#22985Closes#21069
[breaking-change]
This removes the FromError trait, since it can now be expressed using
the new convert::Into trait. All implementations of FromError<E> where
changed to From<E>, and `try!` was changed to use From::from instead.
Because this removes FromError, it is a breaking change, but fixing it
simply requires changing the words `FromError` to `From`, and
`from_error` to `from`.
[breaking-change]
This permits all coercions to be performed in casts, but adds lints to warn in those cases.
Part of this patch moves cast checking to a later stage of type checking. We acquire obligations to check casts as part of type checking where we previously checked them. Once we have type checked a function or module, then we check any cast obligations which have been acquired. That means we have more type information available to check casts (this was crucial to making coercions work properly in place of some casts), but it means that casts cannot feed input into type inference.
[breaking change]
* Adds two new lints for trivial casts and trivial numeric casts, these are warn by default, but can cause errors if you build with warnings as errors. Previously, trivial numeric casts and casts to trait objects were allowed.
* The unused casts lint has gone.
* Interactions between casting and type inference have changed in subtle ways. Two ways this might manifest are:
- You may need to 'direct' casts more with extra type information, for example, in some cases where `foo as _ as T` succeeded, you may now need to specify the type for `_`
- Casts do not influence inference of integer types. E.g., the following used to type check:
```
let x = 42;
let y = &x as *const u32;
```
Because the cast would inform inference that `x` must have type `u32`. This no longer applies and the compiler will fallback to `i32` for `x` and thus there will be a type error in the cast. The solution is to add more type information:
```
let x: u32 = 42;
let y = &x as *const u32;
```
This is a [breaking-change]. When indexing a generic map (hashmap, etc) using the `[]` operator, it is now necessary to borrow explicitly, so change `map[key]` to `map[&key]` (consistent with the `get` routine). However, indexing of string-valued maps with constant strings can now be written `map["abc"]`.
r? @japaric
cc @aturon @Gankro
