This is the kind of change that one is expected to need to make to
accommodate overloaded-`box`.
----
Note that this is not *all* of the changes necessary to accommodate
Issue 22181. It is merely the subset of those cases where there was
already a let-binding in place that made it easy to add the necesasry
type ascription.
(For unnamed intermediate `Box` values, one must go down a different
route; `Box::new` is the option that maximizes portability, but has
potential inefficiency depending on whether the call is inlined.)
----
There is one place worth note, `run-pass/coerce-match.rs`, where I
used an ugly form of `Box<_>` type ascription where I would have
preferred to use `Box::new` to accommodate overloaded-`box`. I
deliberately did not use `Box::new` here, because that is already done
in coerce-match-calls.rs.
----
Precursor for overloaded-`box` and placement-`in`; see Issue 22181.
This changes the type of some public constants/statics in libunicode.
Notably some `&'static &'static [(char, char)]` have changed
to `&'static [(char, char)]`. The regexp crate seems to be the
sole user of these, yet this is technically a [breaking-change]
We were recording stability attributes applied to fields in the
compiler, and even annotating it in the libs, but the compiler didn't
actually do the checks to give errors/warnings in user crates.
Details in the commit messages.
Implements `Debug` for `RwLock` and `arc::Weak` in the same way it is implemented for `rc::Weak` (basically copy & paste).
The lack of this implementation prevents the automatic implementation of `Debug` for structs containing members of these types.
This commit removes many unnecessary `unsafe impl` blocks as well as pushing the
needed implementations to the lowest level possible. I noticed that the bounds
for `RwLock` are a little off when reviewing #22574 and wanted to ensure that we
had our story straight on these implementations.
fmt and hash are pretty straightforward I think. sync is a bit more complex. I thought one or two of the `isize`s ought to be `i32`s, but that would require a bunch of casting (the root cause being the lack of atomics other than isize/usize).
r? @alexcrichton
... to convert between Box and raw pointers. E. g. use
```
let b: Box<Foo> = Box::from_raw(p);
```
instead of
```
let b: Box<Foo> = mem::transmute(p);
```
Patch also changes closure release code in `src/libstd/sys/unix/thread.rs`
when `pthread_create` failed. Raw pointer was transmuted to box of
`FnOnce()` instead of `Thunk`. This code was probably never executed,
because `pthread_create` rarely fails in practice.
This commit removes many unnecessary `unsafe impl` blocks as well as pushing the
needed implementations to the lowest level possible. I noticed that the bounds
for `RwLock` are a little off when reviewing #22574 and wanted to ensure that we
had our story straight on these implementations.
In most places this preserves the current API by adding an explicit
`'static` bound.
Notably absent are some impls like `unsafe impl<T: Send> Send for
Foo<T>` and the `std::thread` module. It is likely that it will be
possible to remove these after auditing the code to ensure restricted
lifetimes are safe.
More progress on #22251.
Rather than stabilize on the current API, we're going to punt this
concern to crates.io, to allow for faster iteration.
If you need this functionality, you might look at https://github.com/carllerche/syncbox
[breaking-change]
This PR replaces uses of `os::getenv` with newly introduced `env::var{,_os}`.
Mostly did this as a background activity to procrastinate from procrastinating.
Tests appear to build and run fine. This includes benchmarks from test/bench directory.
There are a number of holes that the stability lint did not previously cover,
including:
* Types
* Bounds on type parameters on functions and impls
* Where clauses
* Imports
* Patterns (structs and enums)
These holes have all been fixed by overriding the `visit_path` function on the
AST visitor instead of a few specialized cases. This change also necessitated a
few stability changes:
* The `collections::fmt` module is now stable (it was already supposed to be).
* The `thread_local:👿:Key` type is now stable (it was already supposed to
be).
* The `std::rt::{begin_unwind, begin_unwind_fmt}` functions are now stable.
These are required via the `panic!` macro.
* The `std::old_io::stdio::{println, println_args}` functions are now stable.
These are required by the `print!` and `println!` macros.
* The `ops::{FnOnce, FnMut, Fn}` traits are now `#[stable]`. This is required to
make bounds with these traits stable. Note that manual implementations of
these traits are still gated by default, this stability only allows bounds
such as `F: FnOnce()`.
Additionally, the compiler now has special logic to ignore its own generated
`__test` module for the `--test` harness in terms of stability.
Closes#8962Closes#16360Closes#20327
[breaking-change]
This was particularly helpful in the time just after OIBIT's
implementation to make sure things that were supposed to be Copy
continued to be, but it's now creates a lot of noise for types that
intentionally don't want to be Copy.
r? @alexcrichton
This was particularly helpful in the time just after OIBIT's
implementation to make sure things that were supposed to be Copy
continued to be, but it's now creates a lot of noise for types that
intentionally don't want to be Copy.
Use the crates.io crate `rand` (version 0.1 should be a drop in
replacement for `std::rand`) and `rand_macros` (`#[derive_Rand]` should
be a drop-in replacement).
[breaking-change]
This commit performs a final stabilization pass over the std::fmt module,
marking all necessary APIs as stable. One of the more interesting aspects of
this module is that it exposes a good deal of its runtime representation to the
outside world in order for `format_args!` to be able to construct the format
strings. Instead of hacking the compiler to assume that these items are stable,
this commit instead lays out a story for the stabilization and evolution of
these APIs.
There are three primary details used by the `format_args!` macro:
1. `Arguments` - an opaque package of a "compiled format string". This structure
is passed around and the `write` function is the source of truth for
transforming a compiled format string into a string at runtime. This must be
able to be constructed in stable code.
2. `Argument` - an opaque structure representing an argument to a format string.
This is *almost* a trait object as it's just a pointer/function pair, but due
to the function originating from one of many traits, it's not actually a
trait object. Like `Arguments`, this must be constructed from stable code.
3. `fmt::rt` - this module contains the runtime type definitions primarily for
the `rt::Argument` structure. Whenever an argument is formatted with
nonstandard flags, a corresponding `rt::Argument` is generated describing how
the argument is being formatted. This can be used to construct an
`Arguments`.
The primary interface to `std::fmt` is the `Arguments` structure, and as such
this type name is stabilize as-is today. It is expected for libraries to pass
around an `Arguments` structure to represent a pending formatted computation.
The remaining portions are largely "cruft" which would rather not be stabilized,
but due to the stability checks they must be. As a result, almost all pieces
have been renamed to represent that they are "version 1" of the formatting
representation. The theory is that at a later date if we change the
representation of these types we can add new definitions called "version 2" and
corresponding constructors for `Arguments`.
One of the other remaining large questions about the fmt module were how the
pending I/O reform would affect the signatures of methods in the module. Due to
[RFC 526][rfc], however, the writers of fmt are now incompatible with the
writers of io, so this question has largely been solved. As a result the
interfaces are largely stabilized as-is today.
[rfc]: https://github.com/rust-lang/rfcs/blob/master/text/0526-fmt-text-writer.md
Specifically, the following changes were made:
* The contents of `fmt::rt` were all moved under `fmt::rt::v1`
* `fmt::rt` is stable
* `fmt::rt::v1` is stable
* `Error` is stable
* `Writer` is stable
* `Writer::write_str` is stable
* `Writer::write_fmt` is stable
* `Formatter` is stable
* `Argument` has been renamed to `ArgumentV1` and is stable
* `ArgumentV1::new` is stable
* `ArgumentV1::from_uint` is stable
* `Arguments::new_v1` is stable (renamed from `new`)
* `Arguments::new_v1_formatted` is stable (renamed from `with_placeholders`)
* All formatting traits are now stable, as well as the `fmt` method.
* `fmt::write` is stable
* `fmt::format` is stable
* `Formatter::pad_integral` is stable
* `Formatter::pad` is stable
* `Formatter::write_str` is stable
* `Formatter::write_fmt` is stable
* Some assorted top level items which were only used by `format_args!` were
removed in favor of static functions on `ArgumentV1` as well.
* The formatting-flag-accessing methods remain unstable
Within the contents of the `fmt::rt::v1` module, the following actions were
taken:
* Reexports of all enum variants were removed
* All prefixes on enum variants were removed
* A few miscellaneous enum variants were renamed
* Otherwise all structs, fields, and variants were marked stable.
In addition to these actions in the `std::fmt` module, many implementations of
`Show` and `String` were stabilized as well.
In some other modules:
* `ToString` is now stable
* `ToString::to_string` is now stable
* `Vec` no longer implements `fmt::Writer` (this has moved to `String`)
This is a breaking change due to all of the changes to the `fmt::rt` module, but
this likely will not have much impact on existing programs.
Closes#20661
[breaking-change]
