* Add `Rc::would_unwrap(&Self) -> bool` to introspect whether try_unwrap would succeed,
because it's destructive (unlike get_mut).
* Move `rc.downgrade()` to `Rc::downgrade(&Self)` per conventions.
* Deprecate `Rc::weak_count` and `Rc::strong_count` for questionable utility.
* Deprecate `Rc::is_unique` for questionable semantics (there are two kinds of
uniqueness with Weak pointers in play).
* Rename `rc.make_unique()` to `Rc::make_mut(&mut Self)` per conventions, to
avoid uniqueness terminology, and to clarify the relation to `Rc::get_mut`.
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.
This commit is an implementation of [RFC 1184][rfc] which tweaks the behavior of
the `#![no_std]` attribute and adds a new `#![no_core]` attribute. The
`#![no_std]` attribute now injects `extern crate core` at the top of the crate
as well as the libcore prelude into all modules (in the same manner as the
standard library's prelude). The `#![no_core]` attribute disables both std and
core injection.
[rfc]: https://github.com/rust-lang/rfcs/pull/1184
This removes a footgun, since it is a reasonable assumption to make that
pointers to `T` will be aligned to `align_of::<T>()`. This also matches
the behaviour of C/C++. `min_align_of` is now deprecated.
Closes#21611.
This commit moves the free functions in the `rc`, `arc`, and `boxed` modules to
associated functions on their respective types, following the recent trend
towards this pattern. The previous free functions are all left in-place with
`#[deprecated]` pointers towards the new locations.
This commit also deprecates `arc::get_mut` and `Arc::make_unique` with no
replacement as they are racy in the face of weak pointers.
Use stable code in doc examples (libcollections)
Main task is to change from String::from_str to String::from in examples for String
(the latter constructor is stable). While I'm at it, also remove redundant feature flags,
fix some other instances of unstable code in examples (in examples for stable
methods), and remove some use of usize in examples too.
Prefer String::from over from_str; String::from_str is unstable while
String::from is stable. Promote the latter by using it in examples.
Simply migrating unstable function to the closest alternative.
* segfault due to not copying drop flag when coercing
* fat pointer casts
* segfault due to not checking drop flag properly
* debuginfo for DST smart pointers
* unreachable code in drop glue
Refactored code so that the drop-flag values for initialized
(`DTOR_NEEDED`) versus dropped (`DTOR_DONE`) are given explicit names.
Add `mem::dropped()` (which with `DTOR_DONE == 0` is semantically the
same as `mem::zeroed`, but the point is that it abstracts away from
the particular choice of value for `DTOR_DONE`).
Filling-drop needs to use something other than `ptr::read_and_zero`,
so I added such a function: `ptr::read_and_drop`. But, libraries
should not use it if they can otherwise avoid it.
Fixes to tests to accommodate filling-drop.
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.
... 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.
