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]
Per [RFC 517](https://github.com/rust-lang/rfcs/pull/575/), this commit introduces platform-native strings. The API is essentially as described in the RFC.
The WTF-8 implementation is adapted from @SimonSapin's [implementation](https://github.com/SimonSapin/rust-wtf8). To make this work, some encodign and decoding functionality in `libcore` is now exported in a "raw" fashion reusable for WTF-8. These exports are *not* reexported in `std`, nor are they stable.
Per [RFC 517](https://github.com/rust-lang/rfcs/pull/575/), this commit
introduces platform-native strings. The API is essentially as described
in the RFC.
The WTF-8 implementation is adapted from @SimonSapin's
[implementation](https://github.com/SimonSapin/rust-wtf8). To make this
work, some encodign and decoding functionality in `libcore` is now
exported in a "raw" fashion reusable for WTF-8. These exports are *not*
reexported in `std`, nor are they stable.
Spellfix for `Debug` trait documentation. Change "most all types should implement this" to "all types should implement this". Same fix for deprecated `Show` trait.
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]
closes#20953closes#21361
---
In the future, we will likely derive these `impl`s via syntax extensions or using compiler magic (see #20617). For the time being we can use these manual `impl`s.
r? @aturon
cc @burntsushi @Kroisse
This commit deprecates `slice`, `slice_from`, `slice_to` and their
mutable variants in favor of slice notation.
The `as_slice` methods are left intact, for now.
[breaking-change]
This commit marks as `#[stable]`:
* The `Index` and `IndexMut` traits. These are stabilized as taking the
index itself *by reference*; after extensive discussion it was
determined that this is a better match with our choices
elsewhere (e.g. making comparison operators auto-reference), and that
the use cases for by-value indices are better handled through
`IndexSet`.
* The `Range`, `RangeFrom` and `RangeTo` structs, introduced for range
notation.
* Various impls of `Index` and `IndexMut`.
The `FullRange` struct is left unstable as we may wish to rename it to
`RangeFull` in the future.
This commit also *removes* the `Step` trait in favor of direct
implementation of iterator traits on ranges for integers. The `Step`
trait was not a terribly useful factoring internally, and it is likely
that external integer types are best off implementing range iterators
directly. It was removed to simplify the API surface. We can always
reintroduce `Step` later if it turns out to be useful.
Due to this removal, this is a:
[breaking-change]
As discussed with @aturon I added implementations of various op traits for references to built-in types which was already suggested by the ops reform RFC.
The 2nd commit updates the module documentation of core::ops to fully reflect the recent change from pass-by-reference to pass-by-value and expands on the implications for generic code.
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
After PR #19766 added implicit coersions `*mut T -> *const T`, the explicit casts can be removed.
(The number of such casts turned out to be relatively small).
This commit aims to stabilize the `TypeId` abstraction by moving it out of the
`intrinsics` module into the `any` module of the standard library. Specifically,
* `TypeId` is now defined at `std::any::TypeId`
* `TypeId::hash` has been removed in favor of an implementation of `Hash`.
This commit also performs a final pass over the `any` module, confirming the
following:
* `Any::get_type_id` remains unstable as *usage* of the `Any` trait will likely
never require this, and the `Any` trait does not need to be implemented for
any other types. As a result, this implementation detail can remain unstable
until associated statics are implemented.
* `Any::downcast_ref` is now stable
* `Any::downcast_mut` is now stable
* `BoxAny` remains unstable. While a direct impl on `Box<Any>` is allowed today
it does not allow downcasting of trait objects like `Box<Any + Send>` (those
returned from `Thread::join`). This is covered by #18737.
* `BoxAny::downcast` is now stable.
The example of the `Index` and `IndexMut` trait contained too much `Foo`.
It now contains a bit more `Bar` to make things clearer which parts are
defining the type of the index.
I searched for times when we were hiding functions with # in the documentation,
and fixed them to not use it unless neccesary.
I also made random improvements whenever I changed something. For example,
I changed Example to Examples, for consistency.
Fixes#13423
* Not all traits are part of the prelude anymore
* We switched from pass-by-reference to pass-by-value for most traits
* Add some explanations around pass-by-value traits in the context of
generic code and additional implementations for reference types.
While it's unstable and will probably be replaced or "reformed" at some point, it's useful in the mean time to be able to introspect the type system when debugging, and not be limited to sized types.
Fixes#21058
No in-tree users. Ugly interface. Closes#14332.
I just happened to notice that this module still lives and has no users. Assuming we don't want it.
r? @aturon cc @alexcrichton
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 removes the needlessly constricting bound on `intrinsics::type_Id` and `TypeId::of`. Also fixes an ICE where using bounds on type parameters in extern blocks fails to resolve the used traits.
This partially implements the feature staging described in the
[release channel RFC][rc]. It does not yet fully conform to the RFC as
written, but does accomplish its goals sufficiently for the 1.0 alpha
release.
It has three primary user-visible effects:
* On the nightly channel, use of unstable APIs generates a warning.
* On the beta channel, use of unstable APIs generates a warning.
* On the beta channel, use of feature gates generates a warning.
Code that does not trigger these warnings is considered 'stable',
modulo pre-1.0 bugs.
Disabling the warnings for unstable APIs continues to be done in the
existing (i.e. old) style, via `#[allow(...)]`, not that specified in
the RFC. I deem this marginally acceptable since any code that must do
this is not using the stable dialect of Rust.
Use of feature gates is itself gated with the new 'unstable_features'
lint, on nightly set to 'allow', and on beta 'warn'.
The attribute scheme used here corresponds to an older version of the
RFC, with the `#[staged_api]` crate attribute toggling the staging
behavior of the stability attributes, but the user impact is only
in-tree so I'm not concerned about having to make design changes later
(and I may ultimately prefer the scheme here after all, with the
`#[staged_api]` crate attribute).
Since the Rust codebase itself makes use of unstable features the
compiler and build system do a midly elaborate dance to allow it to
bootstrap while disobeying these lints (which would otherwise be
errors because Rust builds with `-D warnings`).
This patch includes one significant hack that causes a
regression. Because the `format_args!` macro emits calls to unstable
APIs it would trigger the lint. I added a hack to the lint to make it
not trigger, but this in turn causes arguments to `println!` not to be
checked for feature gates. I don't presently understand macro
expansion well enough to fix. This is bug #20661.
Closes#16678
[rc]: https://github.com/rust-lang/rfcs/blob/master/text/0507-release-channels.md
Next steps are to disable the existing out-of-tree behavior for stability attributes, and convert the remaining system to be feature-based per the RFC. During the first beta cycle we will set these lints to 'forbid'.
This commit aims to prepare the `std::hash` module for alpha by formalizing its
current interface whileholding off on adding `#[stable]` to the new APIs. The
current usage with the `HashMap` and `HashSet` types is also reconciled by
separating out composable parts of the design. The primary goal of this slight
redesign is to separate the concepts of a hasher's state from a hashing
algorithm itself.
The primary change of this commit is to separate the `Hasher` trait into a
`Hasher` and a `HashState` trait. Conceptually the old `Hasher` trait was
actually just a factory for various states, but hashing had very little control
over how these states were used. Additionally the old `Hasher` trait was
actually fairly unrelated to hashing.
This commit redesigns the existing `Hasher` trait to match what the notion of a
`Hasher` normally implies with the following definition:
trait Hasher {
type Output;
fn reset(&mut self);
fn finish(&self) -> Output;
}
This `Hasher` trait emphasizes that hashing algorithms may produce outputs other
than a `u64`, so the output type is made generic. Other than that, however, very
little is assumed about a particular hasher. It is left up to implementors to
provide specific methods or trait implementations to feed data into a hasher.
The corresponding `Hash` trait becomes:
trait Hash<H: Hasher> {
fn hash(&self, &mut H);
}
The old default of `SipState` was removed from this trait as it's not something
that we're willing to stabilize until the end of time, but the type parameter is
always required to implement `Hasher`. Note that the type parameter `H` remains
on the trait to enable multidispatch for specialization of hashing for
particular hashers.
Note that `Writer` is not mentioned in either of `Hash` or `Hasher`, it is
simply used as part `derive` and the implementations for all primitive types.
With these definitions, the old `Hasher` trait is realized as a new `HashState`
trait in the `collections::hash_state` module as an unstable addition for
now. The current definition looks like:
trait HashState {
type Hasher: Hasher;
fn hasher(&self) -> Hasher;
}
The purpose of this trait is to emphasize that the one piece of functionality
for implementors is that new instances of `Hasher` can be created. This
conceptually represents the two keys from which more instances of a
`SipHasher` can be created, and a `HashState` is what's stored in a
`HashMap`, not a `Hasher`.
Implementors of custom hash algorithms should implement the `Hasher` trait, and
only hash algorithms intended for use in hash maps need to implement or worry
about the `HashState` trait.
The entire module and `HashState` infrastructure remains `#[unstable]` due to it
being recently redesigned, but some other stability decision made for the
`std::hash` module are:
* The `Writer` trait remains `#[experimental]` as it's intended to be replaced
with an `io::Writer` (more details soon).
* The top-level `hash` function is `#[unstable]` as it is intended to be generic
over the hashing algorithm instead of hardwired to `SipHasher`
* The inner `sip` module is now private as its one export, `SipHasher` is
reexported in the `hash` module.
And finally, a few changes were made to the default parameters on `HashMap`.
* The `RandomSipHasher` default type parameter was renamed to `RandomState`.
This renaming emphasizes that it is not a hasher, but rather just state to
generate hashers. It also moves away from the name "sip" as it may not always
be implemented as `SipHasher`. This type lives in the
`std::collections::hash_map` module as `#[unstable]`
* The associated `Hasher` type of `RandomState` is creatively called...
`Hasher`! This concrete structure lives next to `RandomState` as an
implemenation of the "default hashing algorithm" used for a `HashMap`. Under
the hood this is currently implemented as `SipHasher`, but it draws an
explicit interface for now and allows us to modify the implementation over
time if necessary.
There are many breaking changes outlined above, and as a result this commit is
a:
[breaking-change]
This bound is probably unintentional and is unnecessarily
constricting.
To facilitate this change, it was also necessary to modify
resolve to recurse on and resolve type parameters in extern { }
blocks. This fixes an ICE when using bounds on type parameters
during the declaration of intrinsics.
This also adds tests for TypeId on both Sized and Unsized
tests as well as a test for using type parameters and bounds
in extern { } blocks.
This partially implements the feature staging described in the
[release channel RFC][rc]. It does not yet fully conform to the RFC as
written, but does accomplish its goals sufficiently for the 1.0 alpha
release.
It has three primary user-visible effects:
* On the nightly channel, use of unstable APIs generates a warning.
* On the beta channel, use of unstable APIs generates a warning.
* On the beta channel, use of feature gates generates a warning.
Code that does not trigger these warnings is considered 'stable',
modulo pre-1.0 bugs.
Disabling the warnings for unstable APIs continues to be done in the
existing (i.e. old) style, via `#[allow(...)]`, not that specified in
the RFC. I deem this marginally acceptable since any code that must do
this is not using the stable dialect of Rust.
Use of feature gates is itself gated with the new 'unstable_features'
lint, on nightly set to 'allow', and on beta 'warn'.
The attribute scheme used here corresponds to an older version of the
RFC, with the `#[staged_api]` crate attribute toggling the staging
behavior of the stability attributes, but the user impact is only
in-tree so I'm not concerned about having to make design changes later
(and I may ultimately prefer the scheme here after all, with the
`#[staged_api]` crate attribute).
Since the Rust codebase itself makes use of unstable features the
compiler and build system to a midly elaborate dance to allow it to
bootstrap while disobeying these lints (which would otherwise be
errors because Rust builds with `-D warnings`).
This patch includes one significant hack that causes a
regression. Because the `format_args!` macro emits calls to unstable
APIs it would trigger the lint. I added a hack to the lint to make it
not trigger, but this in turn causes arguments to `println!` not to be
checked for feature gates. I don't presently understand macro
expansion well enough to fix. This is bug #20661.
Closes#16678
[rc]: https://github.com/rust-lang/rfcs/blob/master/text/0507-release-channels.md
This commit performs a pass over the implementations of the new `String` trait
in the formatting module. Some implementations were removed as a conservative
move pending an upcoming convention about `String` implementations, and some
were added in order to retain consistency across the libraries. Specifically:
* All "smart pointers" implement `String` now, adding missing implementations
for `Arc` and `Rc`.
* The `Vec<T>` and `[T]` types no longer implement `String`.
* The `*const T` and `*mut T` type no longer implement `String`.
* The `()` type no longer implements `String`.
* The `Path` type's `Show` implementation does not surround itself with `Path
{}` (a minor tweak).
All implementations of `String` in this PR were also marked `#[stable]` to
indicate that the types will continue to implement the `String` trait regardless
of what it looks like.
This commit aims to prepare the `std::hash` module for alpha by formalizing its
current interface whileholding off on adding `#[stable]` to the new APIs. The
current usage with the `HashMap` and `HashSet` types is also reconciled by
separating out composable parts of the design. The primary goal of this slight
redesign is to separate the concepts of a hasher's state from a hashing
algorithm itself.
The primary change of this commit is to separate the `Hasher` trait into a
`Hasher` and a `HashState` trait. Conceptually the old `Hasher` trait was
actually just a factory for various states, but hashing had very little control
over how these states were used. Additionally the old `Hasher` trait was
actually fairly unrelated to hashing.
This commit redesigns the existing `Hasher` trait to match what the notion of a
`Hasher` normally implies with the following definition:
trait Hasher {
type Output;
fn reset(&mut self);
fn finish(&self) -> Output;
}
This `Hasher` trait emphasizes that hashing algorithms may produce outputs other
than a `u64`, so the output type is made generic. Other than that, however, very
little is assumed about a particular hasher. It is left up to implementors to
provide specific methods or trait implementations to feed data into a hasher.
The corresponding `Hash` trait becomes:
trait Hash<H: Hasher> {
fn hash(&self, &mut H);
}
The old default of `SipState` was removed from this trait as it's not something
that we're willing to stabilize until the end of time, but the type parameter is
always required to implement `Hasher`. Note that the type parameter `H` remains
on the trait to enable multidispatch for specialization of hashing for
particular hashers.
Note that `Writer` is not mentioned in either of `Hash` or `Hasher`, it is
simply used as part `derive` and the implementations for all primitive types.
With these definitions, the old `Hasher` trait is realized as a new `HashState`
trait in the `collections::hash_state` module as an unstable addition for
now. The current definition looks like:
trait HashState {
type Hasher: Hasher;
fn hasher(&self) -> Hasher;
}
The purpose of this trait is to emphasize that the one piece of functionality
for implementors is that new instances of `Hasher` can be created. This
conceptually represents the two keys from which more instances of a
`SipHasher` can be created, and a `HashState` is what's stored in a
`HashMap`, not a `Hasher`.
Implementors of custom hash algorithms should implement the `Hasher` trait, and
only hash algorithms intended for use in hash maps need to implement or worry
about the `HashState` trait.
The entire module and `HashState` infrastructure remains `#[unstable]` due to it
being recently redesigned, but some other stability decision made for the
`std::hash` module are:
* The `Writer` trait remains `#[experimental]` as it's intended to be replaced
with an `io::Writer` (more details soon).
* The top-level `hash` function is `#[unstable]` as it is intended to be generic
over the hashing algorithm instead of hardwired to `SipHasher`
* The inner `sip` module is now private as its one export, `SipHasher` is
reexported in the `hash` module.
And finally, a few changes were made to the default parameters on `HashMap`.
* The `RandomSipHasher` default type parameter was renamed to `RandomState`.
This renaming emphasizes that it is not a hasher, but rather just state to
generate hashers. It also moves away from the name "sip" as it may not always
be implemented as `SipHasher`. This type lives in the
`std::collections::hash_map` module as `#[unstable]`
* The associated `Hasher` type of `RandomState` is creatively called...
`Hasher`! This concrete structure lives next to `RandomState` as an
implemenation of the "default hashing algorithm" used for a `HashMap`. Under
the hood this is currently implemented as `SipHasher`, but it draws an
explicit interface for now and allows us to modify the implementation over
time if necessary.
There are many breaking changes outlined above, and as a result this commit is
a:
[breaking-change]
This PR introduces `isize` and `usize` modules to `core` and `std`, and
deprecates the existing `int` and `uint` modules. The rustdoc primitive
type links now point to these new modules.
Due to deprecation this is a:
[breaking-change]
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]
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]
This commit is an implementation of [RFC 494][rfc] which removes the entire
`std::c_vec` module and redesigns the `std::c_str` module as `std::ffi`.
[rfc]: https://github.com/rust-lang/rfcs/blob/master/text/0494-c_str-and-c_vec-stability.md
The interface of the new `CString` is outlined in the linked RFC, the primary
changes being:
* The `ToCStr` trait is gone, meaning the `with_c_str` and `to_c_str` methods
are now gone. These two methods are replaced with a `CString::from_slice`
method.
* The `CString` type is now just a wrapper around `Vec<u8>` with a static
guarantee that there is a trailing nul byte with no internal nul bytes. This
means that `CString` now implements `Deref<Target = [c_char]>`, which is where
it gains most of its methods from. A few helper methods are added to acquire a
slice of `u8` instead of `c_char`, as well as including a slice with the
trailing nul byte if necessary.
* All usage of non-owned `CString` values is now done via two functions inside
of `std::ffi`, called `c_str_to_bytes` and `c_str_to_bytes_with_nul`. These
functions are now the one method used to convert a `*const c_char` to a Rust
slice of `u8`.
Many more details, including newly deprecated methods, can be found linked in
the RFC. This is a:
[breaking-change]
Closes#20444
macro_rules! is like an item that defines a macro. Other items don't have a
trailing semicolon, or use a paren-delimited body.
If there's an argument for matching the invocation syntax, e.g. parentheses for
an expr macro, then I think that applies more strongly to the *inner*
delimiters on the LHS, wrapping the individual argument patterns.
- the self type includes some local type; and,
- type parameters in the self type must be constrained by a local type.
A type parameter is called *constrained* if it appears in some type-parameter of a local type.
Here are some examples that are accepted. In all of these examples, I
assume that `Foo` is a trait defined in another crate. If `Foo` were
defined in the local crate, then all the examples would be legal.
- `impl Foo for LocalType`
- `impl<T> Foo<T> for LocalType` -- T does not appear in Self, so it is OK
- `impl<T> Foo<T> for LocalType<T>` -- T here is constrained by LocalType
- `impl<T> Foo<T> for (LocalType<T>, T)` -- T here is constrained by LocalType
Here are some illegal examples (again, these examples assume that
`Foo` is not local to the current crate):
- `impl Foo for int` -- the Self type is not local
- `impl<T> Foo for T` -- T appears in Self unconstrained by a local type
- `impl<T> Foo for (LocalType, T)` -- T appears in Self unconstrained by a local type
This is a [breaking-change]. For the time being, you can opt out of
the new rules by placing `#[old_orphan_check]` on the trait (and
enabling the feature gate where the trait is defined). Longer term,
you should restructure your traits to avoid the problem. Usually this
means changing the order of parameters so that the "central" type
parameter is in the `Self` position.
As an example of that refactoring, consider the `BorrowFrom` trait:
```rust
pub trait BorrowFrom<Sized? Owned> for Sized? {
fn borrow_from(owned: &Owned) -> &Self;
}
```
As defined, this trait is commonly implemented for custom pointer
types, such as `Arc`. Those impls follow the pattern:
```rust
impl<T> BorrowFrom<Arc<T>> for T {...}
```
Unfortunately, this impl is illegal because the self type `T` is not
local to the current crate. Therefore, we are going to change the order of the parameters,
so that `BorrowFrom` becomes `Borrow`:
```rust
pub trait Borrow<Sized? Borrowed> for Sized? {
fn borrow_from(owned: &Self) -> &Borrowed;
}
```
Now the `Arc` impl is written:
```rust
impl<T> Borrow<T> for Arc<T> { ... }
```
This impl is legal because the self type (`Arc<T>`) is local.
This commit marks as stable those parts of `core::ops` that are in their
final planned form: `Drop`, all of the mathematical operators (`Add`,
`Sub`, etc), `Deref`/`DerefMut`. It leaves the `Index*`, `Slice*` and
`Fn*` traits unstable, as they are still undergoing active changes.
This commit wraps up the adjustments to the iterator for recent language
changes.
* Moves `rposition` from `ExactSizeIterator` to `IteratorExt` using a
`where` clause, thereby removing the `ExactSizeIterator:
DoubleEndedIterator` constraint.
* Merges `MutableDoubleEndedIterator` into `IteratorExt`, renaming
`reverse_` to `reverse_in_place`.
* Merges `IteratorOrdExt`, `IteratorCloneExt` and `CloneIteratorExt`
into `IteratorExt` using `where` clauses.
Marks as `#[stable]`:
* the `iter` module itself
* `FromIterator`, `Extend`
* `Iterator`, `IteratorExt`
* `map`
* `filter`
* `filter_map`
* `skip_while`
* `take_while`
* `scan`
* `flat_map`
* `inspect`
* `collect`
* `fold`
* `all`
* `any`
* `find`
* `rposition`
* `max`, `min`
* Various adapter types related to the above methods
Because of the trait merging, this is a:
[breaking-change]
Many of libstd's macros are now re-exported from libcore and libcollections.
Their libstd definitions have moved to a macros_stage0 module and can disappear
after the next snapshot.
Where the two crates had already diverged, I took the libstd versions as
they're generally newer and better-tested. See e.g. d3c831b, which was a fix to
libstd's assert_eq!() that didn't make it into libcore's.
Fixes#16806.
This commit is an implementation of [RFC 494][rfc] which removes the entire
`std::c_vec` module and redesigns the `std::c_str` module as `std::ffi`.
[rfc]: https://github.com/rust-lang/rfcs/blob/master/text/0494-c_str-and-c_vec-stability.md
The interface of the new `CString` is outlined in the linked RFC, the primary
changes being:
* The `ToCStr` trait is gone, meaning the `with_c_str` and `to_c_str` methods
are now gone. These two methods are replaced with a `CString::from_slice`
method.
* The `CString` type is now just a wrapper around `Vec<u8>` with a static
guarantee that there is a trailing nul byte with no internal nul bytes. This
means that `CString` now implements `Deref<Target = [c_char]>`, which is where
it gains most of its methods from. A few helper methods are added to acquire a
slice of `u8` instead of `c_char`, as well as including a slice with the
trailing nul byte if necessary.
* All usage of non-owned `CString` values is now done via two functions inside
of `std::ffi`, called `c_str_to_bytes` and `c_str_to_bytes_with_nul`. These
functions are now the one method used to convert a `*const c_char` to a Rust
slice of `u8`.
Many more details, including newly deprecated methods, can be found linked in
the RFC. This is a:
[breaking-change]
Closes#20444
* 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.
* The `str` module itself is stable.
* The `StrExt` trait is stable (and impls).
* The `Utf8Error` type is unstable.
* The `from_utf8` function is stable
* Some iterators are now stable:
* `Chars`
* `CharIndices`
* The `MatchIndices` iterator is now unstable
* The public `traits` module is no longer public.
This implements RFC 179 by making the pattern `&<pat>` require matching
against a variable of type `&T`, and introducing the pattern `&mut
<pat>` which only works with variables of type `&mut T`.
The pattern `&mut x` currently parses as `&(mut x)` i.e. a pattern match
through a `&T` or a `&mut T` that binds the variable `x` to have type
`T` and to be mutable. This should be rewritten as follows, for example,
for &mut x in slice.iter() {
becomes
for &x in slice.iter() {
let mut x = x;
Due to this, this is a
[breaking-change]
Closes#20496.
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.
closes#20486closes#20474closes#20441
[breaking-change]
The `Index[Mut]` traits now have one less input parameter, as the return type of the indexing operation is an associated type. This breaks all existing implementations.
---
binop traits (`Add`, `Sub`, etc) now have an associated type for their return type. Also, the RHS input parameter now defaults to `Self` (except for the `Shl` and `Shr` traits). For example, the `Add` trait now looks like this:
``` rust
trait Add<Rhs=Self> {
type Output;
fn add(self, Rhs) -> Self::Output;
}
```
The `Neg` and `Not` traits now also have an associated type for their return type.
This breaks all existing implementations of these traits.
---
Affected traits:
- `Iterator { type Item }`
- `IteratorExt` no input/output types, uses `<Self as Iterator>::Item` in its methods
- `DoubleEndedIterator` no input/output types, uses `<Self as Iterator>::Item` in its methods
- `DoubleEndedIteratorExt` no input/output types, uses `<Self as Iterator>::Item` in its methods
- `RandomAccessIterator` no input/output types
- `ExactSizeIterator` no input/output types, uses `<Self as Iterator>::Item` in its methods
This breaks all the implementations of these traits.
This modifies `Parser::eat_lt` to always split up `<<`s, instead of doing so only when a lifetime name followed or the `force` parameter (now removed) was `true`. This is because `Foo<<TYPE` is now a valid start to a type, whereas previously only `Foo<<LIFETIME` was valid.
This is a [breaking-change]. Change code that looks like this:
```rust
let x = foo as bar << 13;
```
to use parentheses, like this:
```rust
let x = (foo as bar) << 13;
```
Closes#17362.
This corresponds to the JMM memory model's non-volatile reads and writes to shared variables. It provides fairly weak guarantees, but prevents UB (specifically, you will never see a value that was not written _at some point_ to the provided location). It is not part of the C++ memory model and is only legal to provide to LLVM for loads and stores (not fences, atomicrmw, etc.).
Valid uses of this ordering are things like racy counters where you don't care about the operation actually being atomic, just want to avoid UB. It cannot be used for synchronization without additional memory barriers since unordered loads and stores may be reordered freely by the optimizer (this is the main way it differs from relaxed).
Because it is new to Rust and it provides so few guarantees, for now only the intrinsic is provided--this patch doesn't add it to any of the higher-level atomic wrappers.
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 commit is an implementation of [RFC 526][rfc] which is a change to alter
the definition of the old `fmt::FormatWriter`. The new trait, renamed to
`Writer`, now only exposes one method `write_str` in order to guarantee that all
implementations of the formatting traits can only produce valid Unicode.
[rfc]: https://github.com/rust-lang/rfcs/blob/master/text/0526-fmt-text-writer.md
One of the primary improvements of this patch is the performance of the
`.to_string()` method by avoiding an almost-always redundant UTF-8 check. This
is a breaking change due to the renaming of the trait as well as the loss of the
`write` method, but migration paths should be relatively easy:
* All usage of `write` should move to `write_str`. If truly binary data was
being written in an implementation of `Show`, then it will need to use a
different trait or an altogether different code path.
* All usage of `write!` should continue to work as-is with no modifications.
* All usage of `Show` where implementations just delegate to another should
continue to work as-is.
[breaking-change]
Closes#20352
This pass performs a second pass of stabilization through the `std::sync`
module, avoiding modules/types that are being handled in other PRs (e.g.
mutexes, rwlocks, condvars, and channels).
The following items are now stable
* `sync::atomic`
* `sync::atomic::ATOMIC_BOOL_INIT` (was `INIT_ATOMIC_BOOL`)
* `sync::atomic::ATOMIC_INT_INIT` (was `INIT_ATOMIC_INT`)
* `sync::atomic::ATOMIC_UINT_INIT` (was `INIT_ATOMIC_UINT`)
* `sync::Once`
* `sync::ONCE_INIT`
* `sync::Once::call_once` (was `doit`)
* C == `pthread_once(..)`
* Boost == `call_once(..)`
* Windows == `InitOnceExecuteOnce`
* `sync::Barrier`
* `sync::Barrier::new`
* `sync::Barrier::wait` (now returns a `bool`)
* `sync::Semaphore::new`
* `sync::Semaphore::acquire`
* `sync::Semaphore::release`
The following items remain unstable
* `sync::SemaphoreGuard`
* `sync::Semaphore::access` - it's unclear how this relates to the poisoning
story of mutexes.
* `sync::TaskPool` - the semantics of a failing task and whether a thread is
re-attached to a thread pool are somewhat unclear, and the
utility of this type in `sync` is question with respect to
the jobs of other primitives. This type will likely become
stable or move out of the standard library over time.
* `sync::Future` - futures as-is have yet to be deeply re-evaluated with the
recent core changes to Rust's synchronization story, and will
likely become stable in the future but are unstable until
that time comes.
[breaking-change]
r? @huonw or @alexcrichton
Apparently, we have previously rejected an RFC like this. However, since then we removed `{:?}` and so without this debugging gets really difficult as soon as there is a RefCell anywhere, so I believe there is more benefit to adding these impls than there was before. By using "try_borrow" we can avoid panicing in `Show` (I think).
@ huon in response to a comment in #19254: I noticed that `drop()` checks for the ptr being null, so I checked here too. Now I am checking for both, if you're confident I can change to only checking `strong()`.
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]
Yes, really. That definition wouldn't work anyway.
This also fixes repeated entries for `debug_assert!` from libcore docs. Maybe we should warn such macro definitions in the first place?
The first six commits are from an earlier PR (#19858) and have already been reviewed. This PR makes an awful hack in the compiler to accommodate slices both natively and in the index a range form. After a snapshot we can hopefully add the new Index impls and then we can remove these awful hacks.
r? @nikomatsakis (or anyone who knows the compiler, really)
