This commit:
* Introduces `std::convert`, providing an implementation of
RFC 529.
* Deprecates the `AsPath`, `AsOsStr`, and `IntoBytes` traits, all
in favor of the corresponding generic conversion traits.
Consequently, various IO APIs now take `AsRef<Path>` rather than
`AsPath`, and so on. Since the types provided by `std` implement both
traits, this should cause relatively little breakage.
* Deprecates many `from_foo` constructors in favor of `from`.
* Changes `PathBuf::new` to take no argument (creating an empty buffer,
as per convention). The previous behavior is now available as
`PathBuf::from`.
* De-stabilizes `IntoCow`. It's not clear whether we need this separate trait.
Closes#22751Closes#14433
[breaking-change]
This commit clarifies some of the unstable features in the `str` module by
moving them out of the blanket `core` and `collections` features.
The following methods were moved to the `str_char` feature which generally
encompasses decoding specific characters from a `str` and dealing with the
result. It is unclear if any of these methods need to be stabilized for 1.0 and
the most conservative route for now is to continue providing them but to leave
them as unstable under a more specific name.
* `is_char_boundary`
* `char_at`
* `char_range_at`
* `char_at_reverse`
* `char_range_at_reverse`
* `slice_shift_char`
The following methods were moved into the generic `unicode` feature as they are
specifically enabled by the `unicode` crate itself.
* `nfd_chars`
* `nfkd_chars`
* `nfc_chars`
* `graphemes`
* `grapheme_indices`
* `width`
This commit stabilizes essentially all of the new `std::path` API. The
API itself is changed in a couple of ways (which brings it in closer
alignment with the RFC):
* `.` components are now normalized away, unless they appear at the
start of a path. This in turn effects the semantics of e.g. asking for
the file name of `foo/` or `foo/.`, both of which yield `Some("foo")`
now. This semantics is what the original RFC specified, and is also
desirable given early experience rolling out the new API.
* The `parent` function now succeeds if, and only if, the path has at
least one non-root/prefix component. This change affects `pop` as
well.
* The `Prefix` component now involves a separate `PrefixComponent`
struct, to better allow for keeping both parsed and unparsed prefix data.
In addition, the `old_path` module is now deprecated.
Closes#23264
[breaking-change]
This commit performs a stabilization pass over the `std::fs` module now that
it's had some time to bake. The change was largely just adding `#[stable]` tags,
but there are a few APIs that remain `#[unstable]`.
The following apis are now marked `#[stable]`:
* `std::fs` (the name)
* `File`
* `Metadata`
* `ReadDir`
* `DirEntry`
* `OpenOptions`
* `Permissions`
* `File::{open, create}`
* `File::{sync_all, sync_data}`
* `File::set_len`
* `File::metadata`
* Trait implementations for `File` and `&File`
* `OpenOptions::new`
* `OpenOptions::{read, write, append, truncate, create}`
* `OpenOptions::open` - this function was modified, however, to not attempt to
reject cross-platform openings of directories. This means that some platforms
will succeed in opening a directory and others will fail.
* `Metadata::{is_dir, is_file, len, permissions}`
* `Permissions::{readonly, set_readonly}`
* `Iterator for ReadDir`
* `DirEntry::path`
* `remove_file` - like with `OpenOptions::open`, the extra windows code to
remove a readonly file has been removed. This means that removing a readonly
file will succeed on some platforms but fail on others.
* `metadata`
* `rename`
* `copy`
* `hard_link`
* `soft_link`
* `read_link`
* `create_dir`
* `create_dir_all`
* `remove_dir`
* `remove_dir_all`
* `read_dir`
The following apis remain `#[unstable]`.
* `WalkDir` and `walk` - there are many methods by which a directory walk can be
constructed, and it's unclear whether the current semantics are the right
ones. For example symlinks are not handled super well currently. This is now
behind a new `fs_walk` feature.
* `File::path` - this is an extra abstraction which the standard library
provides on top of what the system offers and it's unclear whether we should
be doing so. This is now behind a new `file_path` feature.
* `Metadata::{accessed, modified}` - we do not currently have a good
abstraction for a moment in time which is what these APIs should likely be
returning, so these remain `#[unstable]` for now. These are now behind a new
`fs_time` feature
* `set_file_times` - like with `Metadata::accessed`, we do not currently have
the appropriate abstraction for the arguments here so this API remains
unstable behind the `fs_time` feature gate.
* `PathExt` - the precise set of methods on this trait may change over time and
some methods may be removed. This API remains unstable behind the `path_ext`
feature gate.
* `set_permissions` - we may wish to expose a more granular ability to set the
permissions on a file instead of just a blanket "set all permissions" method.
This function remains behind the `fs` feature.
The following apis are now `#[deprecated]`
* The `TempDir` type is now entirely deprecated and is [located on
crates.io][tempdir] as the `tempdir` crate with [its source][github] at
rust-lang/tempdir.
[tempdir]: https://crates.io/crates/tempdir
[github]: https://github.com/rust-lang/tempdir
The stability of some of these APIs has been questioned over the past few weeks
in using these APIs, and it is intentional that the majority of APIs here are
marked `#[stable]`. The `std::fs` module has a lot of room to grow and the
material is [being tracked in a RFC issue][rfc-issue].
[rfc-issue]: https://github.com/rust-lang/rfcs/issues/939
[breaking-change]
The two main sub-modules, `c_str` and `os_str`, have now had some time to bake
in the standard library. This commits performs a sweep over the modules adding
various stability tags.
The following APIs are now marked `#[stable]`
* `OsString`
* `OsStr`
* `OsString::from_string`
* `OsString::from_str`
* `OsString::new`
* `OsString::into_string`
* `OsString::push` (renamed from `push_os_str`, added an `AsOsStr` bound)
* various trait implementations for `OsString`
* `OsStr::from_str`
* `OsStr::to_str`
* `OsStr::to_string_lossy`
* `OsStr::to_os_string`
* various trait implementations for `OsStr`
* `CString`
* `CStr`
* `NulError`
* `CString::new` - this API's implementation may change as a result of
rust-lang/rfcs#912 but the usage of `CString::new(thing)` looks like it is
unlikely to change. Additionally, the `IntoBytes` bound is also likely to
change but the set of implementors for the trait will not change (despite the
trait perhaps being renamed).
* `CString::from_vec_unchecked`
* `CString::as_bytes`
* `CString::as_bytes_with_nul`
* `NulError::nul_position`
* `NulError::into_vec`
* `CStr::from_ptr`
* `CStr::as_ptr`
* `CStr::to_bytes`
* `CStr::to_bytes_with_nul`
* various trait implementations for `CStr`
The following APIs remain `#[unstable]`
* `OsStr*Ext` traits remain unstable as the organization of `os::platform` is
uncertain still and the traits may change location.
* `AsOsStr` remains unstable as generic conversion traits are likely to be
rethought soon.
The following APIs were deprecated
* `OsString::push_os_str` is now called `push` and takes `T: AsOsStr` instead (a
superset of the previous functionality).
This commit deprecates the majority of std::old_io::fs in favor of std::fs and
its new functionality. Some functions remain non-deprecated but are now behind a
feature gate called `old_fs`. These functions will be deprecated once
suitable replacements have been implemented.
The compiler has been migrated to new `std::fs` and `std::path` APIs where
appropriate as part of this change.
Now that the `std::env` module has had some time to bake this commit marks most
of its APIs as `#[stable]`. Some notable APIs that are **not** stable (and still
use the same `env` feature gate) are:
* `{set,get}_exit_status` - there are still questions about whether this is the
right interface for setting/getting the exit status of a process.
* `page_size` - this may change location in the future or perhaps name as well.
This also effectively closes#22122 as the variants of `VarError` are
`#[stable]` now. (this is done intentionally)
This pulls out the implementations of most built-in lints into a
separate crate, to reduce edit-compile-test iteration times with
librustc_lint and increase parallelism. This should enable lints to be
refactored, added and deleted much more easily as it slashes the
edit-compile cycle to get a minimal working compiler to test with (`make
rustc-stage1`) from
librustc -> librustc_typeck -> ... -> librustc_driver ->
libcore -> ... -> libstd
to
librustc_lint -> librustc_driver -> libcore -> ... libstd
which is significantly faster, mainly due to avoiding the librustc build
itself.
The intention would be to move as much as possible of the infrastructure
into the crate too, but the plumbing is deeply intertwined with librustc
itself at the moment. Also, there are lints for which diagnostics are
registered directly in the compiler code, not in their own crate
traversal, and their definitions have to remain in librustc.
This is a [breaking-change] for direct users of the compiler APIs:
callers of `rustc::session::build_session` or
`rustc::session::build_session_` need to manually call
`rustc_lint::register_builtins` on their return value.
This should make #22206 easier.
Now that the `std::env` module has had some time to bake this commit marks most
of its APIs as `#[stable]`. Some notable APIs that are **not** stable (and still
use the same `env` feature gate) are:
* `{set,get}_exit_status` - there are still questions about whether this is the
right interface for setting/getting the exit status of a process.
* `page_size` - this may change location in the future or perhaps name as well.
This also effectively closes#22122 as the variants of `VarError` are
`#[stable]` now. (this is done intentionally)
This commit moves `std::env` away from the `std::old_io` error type as well as
the `std::old_path` module. Methods returning an error now return `io::Error`
and methods consuming or returning paths use `std::path` instead of
`std::old_path`. This commit does not yet mark these APIs as `#[stable]`.
This commit also migrates `std::old_io::TempDir` to `std::fs::TempDir` with
essentially the exact same API. This type was added to interoperate with the new
path API and has its own `tempdir` feature.
Finally, this commit reverts the deprecation of `std::os` APIs returning the old
path API types. This deprecation can come back once the entire `std::old_path`
module is deprecated.
[breaking-change]
This commit renames the features for the `std::old_io` and `std::old_path`
modules to `old_io` and `old_path` to help facilitate migration to the new APIs.
This is a breaking change as crates which mention the old feature names now need
to be renamed to use the new feature names.
[breaking-change]
This is an implementation of [RFC 578][rfc] which adds a new `std::env` module
to replace most of the functionality in the current `std::os` module. More
details can be found in the RFC itself, but as a summary the following methods
have all been deprecated:
[rfc]: https://github.com/rust-lang/rfcs/pull/578
* `os::args_as_bytes` => `env::args`
* `os::args` => `env::args`
* `os::consts` => `env::consts`
* `os::dll_filename` => no replacement, use `env::consts` directly
* `os::page_size` => `env::page_size`
* `os::make_absolute` => use `env::current_dir` + `join` instead
* `os::getcwd` => `env::current_dir`
* `os::change_dir` => `env::set_current_dir`
* `os::homedir` => `env::home_dir`
* `os::tmpdir` => `env::temp_dir`
* `os::join_paths` => `env::join_paths`
* `os::split_paths` => `env::split_paths`
* `os::self_exe_name` => `env::current_exe`
* `os::self_exe_path` => use `env::current_exe` + `pop`
* `os::set_exit_status` => `env::set_exit_status`
* `os::get_exit_status` => `env::get_exit_status`
* `os::env` => `env::vars`
* `os::env_as_bytes` => `env::vars`
* `os::getenv` => `env::var` or `env::var_string`
* `os::getenv_as_bytes` => `env::var`
* `os::setenv` => `env::set_var`
* `os::unsetenv` => `env::remove_var`
Many function signatures have also been tweaked for various purposes, but the
main changes were:
* `Vec`-returning APIs now all return iterators instead
* All APIs are now centered around `OsString` instead of `Vec<u8>` or `String`.
There is currently on convenience API, `env::var_string`, which can be used to
get the value of an environment variable as a unicode `String`.
All old APIs are `#[deprecated]` in-place and will remain for some time to allow
for migrations. The semantics of the APIs have been tweaked slightly with regard
to dealing with invalid unicode (panic instead of replacement).
The new `std::env` module is all contained within the `env` feature, so crates
must add the following to access the new APIs:
#![feature(env)]
[breaking-change]
The regex library was largely used for non-critical aspects of the compiler and
various external tooling. The library at this point is duplicated with its
out-of-tree counterpart and as such imposes a bit of a maintenance overhead as
well as compile time hit for the compiler itself.
The last major user of the regex library is the libtest library, using regexes
for filters when running tests. This removal means that the filtering has gone
back to substring matching rather than using regexes.
In accordance with [collections reform part 2][rfc] this macro has been moved to
an external [bitflags crate][crate] which is [available though
crates.io][cratesio]. Inside the standard distribution the macro has been moved
to a crate called `rustc_bitflags` for current users to continue using.
[rfc]: https://github.com/rust-lang/rfcs/blob/master/text/0509-collections-reform-part-2.md
[crate]: https://github.com/rust-lang/bitflags
[cratesio]: http://crates.io/crates/bitflags
The major user of `bitflags!` in terms of a public-facing possibly-stable API
today is the `FilePermissions` structure inside of `std::io`. This user,
however, will likely no longer use `bitflags!` after I/O reform has landed. To
prevent breaking APIs today, this structure remains as-is.
Current users of the `bitflags!` macro should add this to their `Cargo.toml`:
bitflags = "0.1"
and this to their crate root:
#[macro_use] extern crate bitflags;
Due to the removal of a public macro, this is a:
[breaking-change]
#### Updated 1/12/2014
I updated the multi-line testcase to current but didn't modify the others. The spew code was broke by the `matches!` macro no longer working and I'm not interested in fixing the testcase.
I additionally added one testcase below.
Errors will in general look similar to below if the error is either `mismatched types` or a few other types. The rest are ignored.
---
#### Extra testcase:
```rust
pub trait Foo {
type A;
fn boo(&self) -> <Self as Foo>::A;
}
struct Bar;
impl Foo for i32 {
type A = u32;
fn boo(&self) -> u32 {
42
}
}
fn foo1<I: Foo<A=Bar>>(x: I) {
let _: Bar = x.boo();
}
fn foo2<I: Foo>(x: I) {
let _: Bar = x.boo();
}
pub fn baz(x: &Foo<A=Bar>) {
let _: Bar = x.boo();
}
pub fn main() {
let a = 42i32;
foo1(a);
baz(&a);
}
```
#### Multi-line output:
```cmd
$ ./rustc test3.rs
test3.rs:20:18: 20:25 error: mismatched types:
expected `Bar`,
found `<I as Foo>::A`
(expected struct `Bar`,
found associated type)
test3.rs:20 let _: Bar = x.boo();
^~~~~~~
test3.rs:31:5: 31:9 error: type mismatch resolving `<i32 as Foo>::A == Bar`:
expected u32,
found struct `Bar`
test3.rs:31 foo1(a);
^~~~
test3.rs:31:5: 31:9 note: required by `foo1`
test3.rs:31 foo1(a);
^~~~
test3.rs:32:9: 32:11 error: type mismatch resolving `<i32 as Foo>::A == Bar`:
expected u32,
found struct `Bar`
test3.rs:32 baz(&a);
^~
test3.rs:32:9: 32:11 note: required for the cast to the object type `Foo`
test3.rs:32 baz(&a);
^~
error: aborting due to 3 previous errors
```
---
This is a continuation of #19203 which I apparently broke by force pushing after it was closed. I'm attempting to add multi-line errors where they are largely beneficial - to help differentiate different types in compiler messages. As before, this is still a simple fix.
#### Testcase:
```rust
struct S;
fn test() -> Option<i32> {
let s: S;
s
}
fn test2() -> Option<i32> {
Ok(7) // Should be Some(7)
}
impl Iterator for S {
type Item = i32;
fn next(&mut self) -> Result<i32, i32> { Ok(7) }
}
fn main(){
test();
test2();
}
```
---
#### Single-line playpen errors:
```cmd
<anon>:6:5: 6:6 error: mismatched types: expected `core::option::Option<int>`, found `S` (expected enum core::option::Option, found struct S)
<anon>:6 s
^
<anon>:10:5: 10:10 error: mismatched types: expected `core::option::Option<int>`, found `core::result::Result<_, _>` (expected enum core::option::Option, found enum core::result::Result)
<anon>:10 Ok(7) // Should be Some(7)
^~~~~
<anon>:14:5: 14:55 error: method `next` has an incompatible type for trait: expected enum core::option::Option, found enum core::result::Result [E0053]
<anon>:14 fn next(&mut self) -> Result<uint, uint> { Ok(7) }
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
error: aborting due to 3 previous errors
playpen: application terminated with error code 101
```
---
#### Multi-line errors:
```cmd
$ ./rustc test.rs
test.rs:6:5: 6:6 error: mismatched types:
expected `core::option::Option<i32>`,
found `S`
(expected enum `core::option::Option`,
found struct `S`)
test.rs:6 s
^
test.rs:10:5: 10:10 error: mismatched types:
expected `core::option::Option<i32>`,
found `core::result::Result<_, _>`
(expected enum `core::option::Option`,
found enum `core::result::Result`)
test.rs:10 Ok(7) // Should be Some(7)
^~~~~
test.rs:15:5: 15:53 error: method `next` has an incompatible type for trait: expected enum `core::option::Option`, found enum `core::result::Result` [E0053]
test.rs:15 fn next(&mut self) -> Result<i32, i32> { Ok(7) }
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
error: aborting due to 3 previous errors
```
---
#### Positive notes
* Vim worked fine with it: https://github.com/rust-lang/rust/pull/19203#issuecomment-66861668
* `make check` didn't find any errors
* Fixed *backtick* placement suggested by @p1start at https://github.com/rust-lang/rust/pull/19203#issuecomment-64062052
#### Negative notes
* Didn't check Emacs support but also wasn't provided a testcase...
* Needs to be tested with macro errors but I don't have a good testcase yet
* I would like to move the `E[0053]` earlier (see https://github.com/rust-lang/rust/issues/19464#issuecomment-65334301) but I don't know how
* It might be better to indent the types slightly like so (but I don't know how):
```cmd
test.rs:6:5: 6:6 error: mismatched types:
expected `core::option::Option<int>`,
found `S`
(expected enum `core::option::Option`,
found struct `S`)
test.rs:6 s
```
* Deep whitespace indentation may be a bad idea because early wrapping will cause misalignment between lines
#### Other
* I thought that compiler flags or something else (environment variables maybe) might be required because of comments against it but now that seems too much of a burden for users and for too little gain.
* There was concern that it will make large quantities of errors difficult to distinguish but I don't find that an issue. They both look awful and multi-line errors makes the types easier to understand.
---
#### Single lined spew:
```cmd
$ rustc test2.rs
test2.rs:161:9: 170:10 error: method `next` has an incompatible type for trait: expected enum core::option::Option, found enum core::result::Result [E0053]
test2.rs:161 fn next(&mut self) -> Result<&'a str, int> {
test2.rs:162 self.curr = self.next;
test2.rs:163
test2.rs:164 if let (Some(open), Some(close)) = Parens::find_parens(self.all, self.next) {
test2.rs:165 self.next = if self.all.char_at(self.next) == '(' { close }
test2.rs:166 else { open }
...
test2.rs:164:21: 164:31 error: mismatched types: expected `core::result::Result<uint, int>`, found `core::option::Option<_>` (expected enum core::result::Result, found enum core::option::Option)
test2.rs:164 if let (Some(open), Some(close)) = Parens::find_parens(self.all, self.next) {
^~~~~~~~~~
test2.rs:164:33: 164:44 error: mismatched types: expected `core::result::Result<uint, int>`, found `core::option::Option<_>` (expected enum core::result::Result, found enum core::option::Option)
test2.rs:164 if let (Some(open), Some(close)) = Parens::find_parens(self.all, self.next) {
^~~~~~~~~~~
test2.rs:169:40: 169:76 error: mismatched types: expected `core::result::Result<&'a str, int>`, found `core::option::Option<&str>` (expected enum core::result::Result, found enum core::option::Option)
test2.rs:169 if self.curr != self.len { Some(self.all[self.curr..self.next]) } else { None }
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
test2.rs:169:86: 169:90 error: mismatched types: expected `core::result::Result<&'a str, int>`, found `core::option::Option<_>` (expected enum core::result::Result, found enum core::option::Option)
test2.rs:169 if self.curr != self.len { Some(self.all[self.curr..self.next]) } else { None }
^~~~
test2.rs:205:14: 205:18 error: mismatched types: expected `core::result::Result<uint, int>`, found `core::option::Option<uint>` (expected enum core::result::Result, found enum core::option::Option)
test2.rs:205 (open, close)
^~~~
test2.rs:205:20: 205:25 error: mismatched types: expected `core::result::Result<uint, int>`, found `core::option::Option<uint>` (expected enum core::result::Result, found enum core::option::Option)
test2.rs:205 (open, close)
^~~~~
test2.rs:210:21: 210:31 error: mismatched types: expected `core::result::Result<uint, int>`, found `core::option::Option<_>` (expected enum core::result::Result, found enum core::option::Option)
test2.rs:210 if let (Some(open), _) = Parens::find_parens(self.all, 0) {
^~~~~~~~~~
test2.rs:210:13: 212:28 error: mismatched types: expected `core::option::Option<&'a int>`, found `core::option::Option<&str>` (expected int, found str)
test2.rs:210 if let (Some(open), _) = Parens::find_parens(self.all, 0) {
test2.rs:211 Some(self.all[0..open])
test2.rs:212 } else { None }
test2.rs:299:48: 299:58 error: mismatched types: expected `Box<translate::Entity>`, found `collections::vec::Vec<_>` (expected box, found struct collections::vec::Vec)
test2.rs:299 pub fn new() -> Entity { Entity::Group(Vec::new()) }
^~~~~~~~~~
test2.rs:359:51: 359:58 error: type `&mut Box<translate::Entity>` does not implement any method in scope named `push`
test2.rs:359 Entity::Group(ref mut vec) => vec.push(e),
^~~~~~~
test2.rs:366:51: 366:85 error: type `&mut Box<translate::Entity>` does not implement any method in scope named `push`
test2.rs:366 Entity::Group(ref mut vec) => vec.push(Entity::Inner(s.to_string())),
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
error: aborting due to 12 previous errors
```
---
#### Multi-line spew:
```cmd
$ ./rustc test2.rs
test2.rs:161:9: 170:10 error: method `next` has an incompatible type for trait:
expected enum `core::option::Option`,
found enum `core::result::Result` [E0053]
test2.rs:161 fn next(&mut self) -> Result<&'a str, int> {
test2.rs:162 self.curr = self.next;
test2.rs:163
test2.rs:164 if let (Some(open), Some(close)) = Parens::find_parens(self.all, self.next) {
test2.rs:165 self.next = if self.all.char_at(self.next) == '(' { close }
test2.rs:166 else { open }
...
test2.rs:164:21: 164:31 error: mismatched types:
expected `core::result::Result<uint, int>`,
found `core::option::Option<_>`
(expected enum `core::result::Result`,
found enum `core::option::Option`)
test2.rs:164 if let (Some(open), Some(close)) = Parens::find_parens(self.all, self.next) {
^~~~~~~~~~
test2.rs:164:33: 164:44 error: mismatched types:
expected `core::result::Result<uint, int>`,
found `core::option::Option<_>`
(expected enum `core::result::Result`,
found enum `core::option::Option`)
test2.rs:164 if let (Some(open), Some(close)) = Parens::find_parens(self.all, self.next) {
^~~~~~~~~~~
test2.rs:169:40: 169:76 error: mismatched types:
expected `core::result::Result<&'a str, int>`,
found `core::option::Option<&str>`
(expected enum `core::result::Result`,
found enum `core::option::Option`)
test2.rs:169 if self.curr != self.len { Some(self.all[self.curr..self.next]) } else { None }
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
test2.rs:169:86: 169:90 error: mismatched types:
expected `core::result::Result<&'a str, int>`,
found `core::option::Option<_>`
(expected enum `core::result::Result`,
found enum `core::option::Option`)
test2.rs:169 if self.curr != self.len { Some(self.all[self.curr..self.next]) } else { None }
^~~~
test2.rs:205:14: 205:18 error: mismatched types:
expected `core::result::Result<uint, int>`,
found `core::option::Option<uint>`
(expected enum `core::result::Result`,
found enum `core::option::Option`)
test2.rs:205 (open, close)
^~~~
test2.rs:205:20: 205:25 error: mismatched types:
expected `core::result::Result<uint, int>`,
found `core::option::Option<uint>`
(expected enum `core::result::Result`,
found enum `core::option::Option`)
test2.rs:205 (open, close)
^~~~~
test2.rs:210:21: 210:31 error: mismatched types:
expected `core::result::Result<uint, int>`,
found `core::option::Option<_>`
(expected enum `core::result::Result`,
found enum `core::option::Option`)
test2.rs:210 if let (Some(open), _) = Parens::find_parens(self.all, 0) {
^~~~~~~~~~
test2.rs:210:13: 212:28 error: mismatched types:
expected `core::option::Option<&'a int>`,
found `core::option::Option<&str>`
(expected int,
found str)
test2.rs:210 if let (Some(open), _) = Parens::find_parens(self.all, 0) {
test2.rs:211 Some(self.all[0..open])
test2.rs:212 } else { None }
test2.rs:229:57: 229:96 error: the trait `core::ops::Fn<(char,), bool>` is not implemented for the type `|char| -> bool`
test2.rs:229 .map(|s| s.trim_chars(|c: char| c.is_whitespace()))
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
test2.rs:238:46: 239:75 error: type `core::str::CharSplits<'_, |char| -> bool>` does not implement any method in scope named `filter_map`
test2.rs:238 .filter_map(|s| if !s.is_empty() { Some(s.trim_chars('\'')) }
test2.rs:239 else { None })
test2.rs:237:46: 237:91 error: the trait `core::ops::Fn<(char,), bool>` is not implemented for the type `|char| -> bool`
test2.rs:237 let vec: Vec<&str> = value[].split(|c: char| matches!(c, '(' | ')' | ','))
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
test2.rs:238:65: 238:77 error: the type of this value must be known in this context
test2.rs:238 .filter_map(|s| if !s.is_empty() { Some(s.trim_chars('\'')) }
^~~~~~~~~~~~
test2.rs:299:48: 299:58 error: mismatched types:
expected `Box<translate::Entity>`,
found `collections::vec::Vec<_>`
(expected box,
found struct `collections::vec::Vec`)
test2.rs:299 pub fn new() -> Entity { Entity::Group(Vec::new()) }
^~~~~~~~~~
test2.rs:321:36: 322:65 error: type `core::str::CharSplits<'_, |char| -> bool>` does not implement any method in scope named `filter_map`
test2.rs:321 .filter_map(|s| if !s.is_empty() { Some(s.trim_chars('\'')) }
test2.rs:322 else { None })
test2.rs:320:36: 320:81 error: the trait `core::ops::Fn<(char,), bool>` is not implemented for the type `|char| -> bool`
test2.rs:320 let vec: Vec<&str> = s.split(|c: char| matches!(c, '(' | ')' | ','))
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
test2.rs:321:55: 321:67 error: the type of this value must be known in this context
test2.rs:321 .filter_map(|s| if !s.is_empty() { Some(s.trim_chars('\'')) }
^~~~~~~~~~~~
test2.rs:359:51: 359:58 error: type `&mut Box<translate::Entity>` does not implement any method in scope named `push`
test2.rs:359 Entity::Group(ref mut vec) => vec.push(e),
^~~~~~~
test2.rs:366:51: 366:85 error: type `&mut Box<translate::Entity>` does not implement any method in scope named `push`
test2.rs:366 Entity::Group(ref mut vec) => vec.push(Entity::Inner(s.to_string())),
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
error: aborting due to 24 previous errors
```
Closes#18946#19464
cc @P1start @jakub- @tomjakubowski @kballard @chris-morgan
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.
To avoid using the feauture, change uses of `box <expr>` to
`Box::new(<expr>)` alternative, as noted by the feature gate message.
(Note that box patterns have no analogous trivial replacement, at
least not in general; you need to revise the code to do a partial
match, deref, and then the rest of the match.)
[breaking-change]
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
