Commit Graph

162 Commits

Author SHA1 Message Date
Tamir Duberstein b3f50caee0 *: remove crate_{name,type} attributes
Fixes #41701.
2017-08-25 16:18:21 -04:00
Scott McMurray c4cb2d1f2e Add [T]::swap_with_slice
The safe version of a method from ptr, like [T]::copy_from_slice
2017-08-21 22:20:00 -07:00
bors ddaab61101 Auto merge of #43373 - alexcrichton:stabilize-1.20.0, r=aturon
Stabilize more APIs for the 1.20.0 release

In addition to the few stabilizations that have already landed, this cleans up the remaining APIs that are in `final-comment-period` right now to be stable by the 1.20.0 release
2017-07-26 23:40:48 +00:00
Alex Crichton 16707d4348 std: Stabilize the str_{mut,box}_extras feature
Stabilizes

* `<&mut str>::as_bytes_mut`
* `<Box<str>>::into_boxed_bytes`
* `std::str::from_boxed_utf8_unchecked`
* `std::str::from_utf8_mut`
* `std::str::from_utf8_unchecked_mut`

Closes #41119
2017-07-25 07:10:42 -07:00
Alex Crichton daeb6077c8 std: Stabilize manually_drop feature
Stabilizes

* `core::mem::ManuallyDrop`
* `std::mem::ManuallyDrop`
* `ManuallyDrop::new`
* `ManuallyDrop::into_inner`
* `ManuallyDrop::drop`
* `Deref for ManuallyDrop`
* `DerefMut for ManuallyDrop`

Closes #40673
2017-07-25 07:09:31 -07:00
Alex Crichton 46de2af063 std: Stabilize str_checked_slicing feature
Stabilized

* `<str>::get`
* `<str>::get_mut`
* `<str>::get_unchecked`
* `<str>::get_unchecked_mut`

Closes #39932
2017-07-25 07:09:31 -07:00
Alex Crichton 4c9c6e824b std: Stabilize char_escape_debug
Stabilizes:

* `<char>::escape_debug`
* `std::char::EscapeDebug`

Closes #35068
2017-07-25 07:09:31 -07:00
Alex Crichton 9010567dcc Bump master to 1.21.0
This commit bumps the master branch's version to 1.21.0 and also updates the
bootstrap compiler from the freshly minted beta release.
2017-07-25 07:03:19 -07:00
Vadim Petrochenkov 465ada623a Fix checking for missing stability annotations
Remove couple of unnecessary `#![feature(staged_api)]`.
2017-07-16 23:15:07 +03:00
Alex Crichton 695dee063b rustc: Implement the #[global_allocator] attribute
This PR is an implementation of [RFC 1974] which specifies a new method of
defining a global allocator for a program. This obsoletes the old
`#![allocator]` attribute and also removes support for it.

[RFC 1974]: https://github.com/rust-lang/rfcs/pull/197

The new `#[global_allocator]` attribute solves many issues encountered with the
`#![allocator]` attribute such as composition and restrictions on the crate
graph itself. The compiler now has much more control over the ABI of the
allocator and how it's implemented, allowing much more freedom in terms of how
this feature is implemented.

cc #27389
2017-07-05 14:37:01 -07:00
bors 1d2db7b9e8 Auto merge of #43010 - stjepang:stabilize-sort-unstable, r=alexcrichton
Stabilize feature sort_unstable

Closes #40585
2017-07-02 23:54:32 +00:00
Stjepan Glavina 21149bcd53 Fix lint errors 2017-07-02 19:14:16 +02:00
Steven Fackler 0a9c13624d Revert "Stabilize RangeArgument"
This reverts commit 143206d54d.
2017-06-30 08:34:53 -10:00
Steven Fackler 143206d54d Stabilize RangeArgument
Move it and Bound to core::ops while we're at it.

Closes #30877
2017-06-24 19:20:57 -07:00
Felix S. Klock II 066fafe206 Add API for Alloc trait.
Includes `alloc_zeroed` method that `RawVec` has come to depend on.

Exposed private `Layout::from_size_align` ctor to be `pub`, and added
explicit conditions for when it will panic (namely, when `align` is
not power-of-two, or if rounding up `size` to a multiple of `align`
overflows). Normalized all `Layout` construction to go through
`Layout::from_size_align`.

Addressed review feedback regarding `struct Layout` and zero-sized
layouts.

Restrict specification for `dealloc`, adding additional constraint
that the given alignment has to match that used to allocate the block.
(This is a maximally conservative constraint on the alignment. An open
question to resolve (before stabilization) is whether we can return to
a looser constraint such as the one previously specified.)

Split `fn realloc_in_place` into separate `fn grow_in_place` and `fn
shrink_in_place` methods, which have default impls that check against
usable_size for reuse. Make `realloc` default impl try `grow_in_place`
or `shrink_in_place` as appropriate before fallback on
alloc+copy+dealloc.

Drive-by: When reviewing calls to `padding_needed_for`, discovered
what I think was an over-conservative choice for its argument
alignment.  Namely, in `fn extend`, we automatically realign the whole
resulting layout to satisfy both old (self) and new alignments. When
the old alignment exceeds the new, this means we would insert
unnecessary padding. So I changed the code to pass in `next.align`
instead of `new_align` to `padding_needed_for`.

Replaced ref to `realloc_in_place` with `grow_in_place`/`shrink_in_place`.

Revised docs replacing my idiosyncratic style of `fn foo` with just
`foo` when referring to the function or method `foo`.

(Alpha-renamed `Allocator` to `Alloc`.)

Post-rebased, added `Debug` derive for `allocator::Excess` to satisfy
`missing_debug_implementations`.
2017-06-15 23:48:12 +02:00
Murarth eadda7665e Merge crate collections into alloc 2017-06-13 23:37:34 -07:00
Alex Crichton 5daf557a77 Update stage0 bootstrap compiler
We've got a freshly minted beta compiler, let's update to use that on nightly!
This has a few other changes associated with it as well

* A bump to the rustc version number (to 1.19.0)
* Movement of the `cargo` and `rls` submodules to their "proper" location in
  `src/tools/{cargo,rls}`. Now that Cargo workspaces support the `exclude`
  option this can work.
* Updates of the `cargo` and `rls` submodules to their master branches.
* Tweak to the `src/stage0.txt` format to be more amenable for Cargo version
  numbers. On the beta channel Cargo will bootstrap from a different version
  than rustc (e.g. the version numbers are different), so we need different
  configuration for this.
* Addition of `dev` as a readable key in the `src/stage0.txt` format. If present
  then stage0 compilers are downloaded from `dev-static.rust-lang.org` instead
  of `static.rust-lang.org`. This is added to accomodate our updated release
  process with Travis and AppVeyor.
2017-04-29 12:11:14 -07:00
bors dad9814eb0 Auto merge of #41258 - clarcharr:str_box_extras, r=Kimundi
More methods for str boxes. (reduce Box<[u8]> ↔ Box<str> transmutes)

This is a follow-up to #41096 that adds safer methods for converting between `Box<str>` and `Box<[u8]>`. They're gated under a different feature from the `&mut str` methods because they may be too niche to include in public APIs, although having them internally helps reduce the number of transmutes the standard library uses.

What's added:

* `From<Box<str>> for Box<[u8]>`
* `<Box<str>>::into_boxed_bytes` (just calls `Into::into`)
* `alloc::str` (new module)
* `from_boxed_utf8` and `from_boxed_utf8_unchecked`, defined in `alloc:str`, exported in `collections::str`
* exports `from_utf8_mut` in `collections::str` (missed from previous PR)
2017-04-26 06:18:17 +00:00
Clar Charr c66c6e9697 More methods for str boxes. 2017-04-24 17:51:49 -04:00
Ariel Ben-Yehuda ece6c8434b cache attributes of items from foreign crates
this avoids parsing item attributes on each call to `item_attrs`, which takes
off 33% (!) of translation time and 50% (!) of trans-item collection time.
2017-04-22 21:00:50 +03:00
Denis Andrejew 339bdc158f Fix typo in liballoc/lib.rs 2017-01-28 22:16:16 +00:00
Seo Sanghyeon d350c9b15f Rollup merge of #38664 - apasel422:may-dangle, r=pnkfelix
Replace uses of `#[unsafe_destructor_blind_to_params]` with `#[may_dangle]`

CC #34761

r? @pnkfelix
2017-01-10 20:27:41 +09:00
Alex Crichton 9b0b5b45db Remove not(stage0) from deny(warnings)
Historically this was done to accommodate bugs in lints, but there hasn't been a
bug in a lint since this feature was added which the warnings affected. Let's
completely purge warnings from all our stages by denying warnings in all stages.
This will also assist in tracking down `stage0` code to be removed whenever
we're updating the bootstrap compiler.
2016-12-29 21:07:20 -08:00
Andrew Paseltiner ca9b07bbc9 Replace uses of #[unsafe_destructor_blind_to_params] with #[may_dangle]
CC #34761
2016-12-28 17:47:10 -05:00
bors 6a495f71ff Auto merge of #37492 - japaric:no-atomics-alloc, r=brson
make `alloc` and `collections` compilable for thumbv6m-none-eabi

by cfging away `alloc::Arc` and changing OOM to abort for this target

r? @alexcrichton
cc @thejpster
2016-12-09 04:02:51 +00:00
Ulrik Sverdrup d53f82c1d0 alloc: Forward ExactSizeIterator methods in Iterator for Box<I> 2016-12-04 15:46:37 +01:00
Cristi Cobzarenco 651cf58f2e Add {into,from}_raw to Rc and Arc 2016-11-05 00:50:41 +00:00
Jorge Aparicio 907d2a1aeb make alloc and collections compilable for thumbv6m-none-eabi
by cfging away `alloc::Arc` and changing OOM to abort for this target
2016-10-30 22:14:05 -05:00
Brian Anderson 3b49c60ab7 Remove stage0 hacks 2016-09-28 23:17:56 +00:00
Andrew Paseltiner 2b10df7f24 Replace unnecessary uses of TraitObject with casts 2016-08-26 06:37:36 -04:00
Eduard Burtescu 119508cdb4 Remove drop flags from structs and enums implementing Drop. 2016-08-24 13:23:37 +03:00
Steven Allen de91872a33 Add a FusedIterator trait.
This trait can be used to avoid the overhead of a fuse wrapper when an iterator
is already well-behaved.

Conforming to: RFC 1581
Closes: #35602
2016-08-18 12:16:29 -04:00
Alex Crichton cae91d7c8c std: Stabilize APIs for the 1.10 release
This commit applies the FCP decisions made by the libs team for the 1.10 cycle,
including both new stabilizations and deprecations. Specifically, the list of
APIs is:

Stabilized:

* `os::windows::fs::OpenOptionsExt::access_mode`
* `os::windows::fs::OpenOptionsExt::share_mode`
* `os::windows::fs::OpenOptionsExt::custom_flags`
* `os::windows::fs::OpenOptionsExt::attributes`
* `os::windows::fs::OpenOptionsExt::security_qos_flags`
* `os::unix::fs::OpenOptionsExt::custom_flags`
* `sync::Weak::new`
* `Default for sync::Weak`
* `panic::set_hook`
* `panic::take_hook`
* `panic::PanicInfo`
* `panic::PanicInfo::payload`
* `panic::PanicInfo::location`
* `panic::Location`
* `panic::Location::file`
* `panic::Location::line`
* `ffi::CStr::from_bytes_with_nul`
* `ffi::CStr::from_bytes_with_nul_unchecked`
* `ffi::FromBytesWithNulError`
* `fs::Metadata::modified`
* `fs::Metadata::accessed`
* `fs::Metadata::created`
* `sync::atomic::Atomic{Usize,Isize,Bool,Ptr}::compare_exchange`
* `sync::atomic::Atomic{Usize,Isize,Bool,Ptr}::compare_exchange_weak`
* `collections::{btree,hash}_map::{Occupied,Vacant,}Entry::key`
* `os::unix::net::{UnixStream, UnixListener, UnixDatagram, SocketAddr}`
* `SocketAddr::is_unnamed`
* `SocketAddr::as_pathname`
* `UnixStream::connect`
* `UnixStream::pair`
* `UnixStream::try_clone`
* `UnixStream::local_addr`
* `UnixStream::peer_addr`
* `UnixStream::set_read_timeout`
* `UnixStream::set_write_timeout`
* `UnixStream::read_timeout`
* `UnixStream::write_Timeout`
* `UnixStream::set_nonblocking`
* `UnixStream::take_error`
* `UnixStream::shutdown`
* Read/Write/RawFd impls for `UnixStream`
* `UnixListener::bind`
* `UnixListener::accept`
* `UnixListener::try_clone`
* `UnixListener::local_addr`
* `UnixListener::set_nonblocking`
* `UnixListener::take_error`
* `UnixListener::incoming`
* RawFd impls for `UnixListener`
* `UnixDatagram::bind`
* `UnixDatagram::unbound`
* `UnixDatagram::pair`
* `UnixDatagram::connect`
* `UnixDatagram::try_clone`
* `UnixDatagram::local_addr`
* `UnixDatagram::peer_addr`
* `UnixDatagram::recv_from`
* `UnixDatagram::recv`
* `UnixDatagram::send_to`
* `UnixDatagram::send`
* `UnixDatagram::set_read_timeout`
* `UnixDatagram::set_write_timeout`
* `UnixDatagram::read_timeout`
* `UnixDatagram::write_timeout`
* `UnixDatagram::set_nonblocking`
* `UnixDatagram::take_error`
* `UnixDatagram::shutdown`
* RawFd impls for `UnixDatagram`
* `{BTree,Hash}Map::values_mut`
* `<[_]>::binary_search_by_key`

Deprecated:

* `StaticCondvar` - this, and all other static synchronization primitives
                    below, are usable today through the lazy-static crate on
                    stable Rust today. Additionally, we'd like the non-static
                    versions to be directly usable in a static context one day,
                    so they're unlikely to be the final forms of the APIs in any
                    case.
* `CONDVAR_INIT`
* `StaticMutex`
* `MUTEX_INIT`
* `StaticRwLock`
* `RWLOCK_INIT`
* `iter::Peekable::is_empty`

Closes #27717
Closes #27720
cc #27784 (but encode methods still exist)
Closes #30014
Closes #30425
Closes #30449
Closes #31190
Closes #31399
Closes #31767
Closes #32111
Closes #32281
Closes #32312
Closes #32551
Closes #33018
2016-05-24 09:00:39 -07:00
Amanieu d'Antras 9a28d4edc9 Change Arc to use compare_exchange instead of compare_and_swap 2016-03-31 13:15:20 +01:00
Alex Crichton 0d5cfd9117 mk: Distribute fewer TARGET_CRATES
Right now everything in TARGET_CRATES is built by default for all non-fulldeps
tests and is distributed by default for all target standard library packages.
Currenly this includes a number of unstable crates which are rarely used such as
`graphviz` and `rbml`>

This commit trims down the set of `TARGET_CRATES`, moves a number of tests to
`*-fulldeps` as a result, and trims down the dependencies of libtest so we can
distribute fewer crates in the `rust-std` packages.
2016-03-07 13:05:12 -08:00
Alex Crichton b643782a10 std: Stabilize APIs for the 1.8 release
This commit is the result of the FCPs ending for the 1.8 release cycle for both
the libs and the lang suteams. The full list of changes are:

Stabilized

* `braced_empty_structs`
* `augmented_assignments`
* `str::encode_utf16` - renamed from `utf16_units`
* `str::EncodeUtf16` - renamed from `Utf16Units`
* `Ref::map`
* `RefMut::map`
* `ptr::drop_in_place`
* `time::Instant`
* `time::SystemTime`
* `{Instant,SystemTime}::now`
* `{Instant,SystemTime}::duration_since` - renamed from `duration_from_earlier`
* `{Instant,SystemTime}::elapsed`
* Various `Add`/`Sub` impls for `Time` and `SystemTime`
* `SystemTimeError`
* `SystemTimeError::duration`
* Various impls for `SystemTimeError`
* `UNIX_EPOCH`
* `ops::{Add,Sub,Mul,Div,Rem,BitAnd,BitOr,BitXor,Shl,Shr}Assign`

Deprecated

* Scoped TLS (the `scoped_thread_local!` macro)
* `Ref::filter_map`
* `RefMut::filter_map`
* `RwLockReadGuard::map`
* `RwLockWriteGuard::map`
* `Condvar::wait_timeout_with`

Closes #27714
Closes #27715
Closes #27746
Closes #27748
Closes #27908
Closes #29866
2016-02-29 09:05:33 -08:00
John Kåre Alsaker 8ade080412 Fix liballoc dependencies 2016-02-21 15:32:43 +01:00
Alex Crichton cb343c33ac Fix warnings during tests
The deny(warnings) attribute is now enabled for tests so we need to weed out
these warnings as well.
2016-01-26 09:29:28 -08:00
Alex Crichton 2273b52023 mk: Move from -D warnings to #![deny(warnings)]
This commit removes the `-D warnings` flag being passed through the makefiles to
all crates to instead be a crate attribute. We want these attributes always
applied for all our standard builds, and this is more amenable to Cargo-based
builds as well.

Note that all `deny(warnings)` attributes are gated with a `cfg(stage0)`
attribute currently to match the same semantics we have today
2016-01-24 20:35:55 -08:00
Alex Crichton 9a4f43b9b6 std: Stabilize APIs for the 1.7 release
This commit stabilizes and deprecates the FCP (final comment period) APIs for
the upcoming 1.7 beta release. The specific APIs which changed were:

Stabilized

* `Path::strip_prefix` (renamed from `relative_from`)
* `path::StripPrefixError` (new error type returned from `strip_prefix`)
* `Ipv4Addr::is_loopback`
* `Ipv4Addr::is_private`
* `Ipv4Addr::is_link_local`
* `Ipv4Addr::is_multicast`
* `Ipv4Addr::is_broadcast`
* `Ipv4Addr::is_documentation`
* `Ipv6Addr::is_unspecified`
* `Ipv6Addr::is_loopback`
* `Ipv6Addr::is_unique_local`
* `Ipv6Addr::is_multicast`
* `Vec::as_slice`
* `Vec::as_mut_slice`
* `String::as_str`
* `String::as_mut_str`
* `<[T]>::clone_from_slice` - the `usize` return value is removed
* `<[T]>::sort_by_key`
* `i32::checked_rem` (and other signed types)
* `i32::checked_neg` (and other signed types)
* `i32::checked_shl` (and other signed types)
* `i32::checked_shr` (and other signed types)
* `i32::saturating_mul` (and other signed types)
* `i32::overflowing_add` (and other signed types)
* `i32::overflowing_sub` (and other signed types)
* `i32::overflowing_mul` (and other signed types)
* `i32::overflowing_div` (and other signed types)
* `i32::overflowing_rem` (and other signed types)
* `i32::overflowing_neg` (and other signed types)
* `i32::overflowing_shl` (and other signed types)
* `i32::overflowing_shr` (and other signed types)
* `u32::checked_rem` (and other unsigned types)
* `u32::checked_neg` (and other unsigned types)
* `u32::checked_shl` (and other unsigned types)
* `u32::saturating_mul` (and other unsigned types)
* `u32::overflowing_add` (and other unsigned types)
* `u32::overflowing_sub` (and other unsigned types)
* `u32::overflowing_mul` (and other unsigned types)
* `u32::overflowing_div` (and other unsigned types)
* `u32::overflowing_rem` (and other unsigned types)
* `u32::overflowing_neg` (and other unsigned types)
* `u32::overflowing_shl` (and other unsigned types)
* `u32::overflowing_shr` (and other unsigned types)
* `ffi::IntoStringError`
* `CString::into_string`
* `CString::into_bytes`
* `CString::into_bytes_with_nul`
* `From<CString> for Vec<u8>`
* `From<CString> for Vec<u8>`
* `IntoStringError::into_cstring`
* `IntoStringError::utf8_error`
* `Error for IntoStringError`

Deprecated

* `Path::relative_from` - renamed to `strip_prefix`
* `Path::prefix` - use `components().next()` instead
* `os::unix::fs` constants - moved to the `libc` crate
* `fmt::{radix, Radix, RadixFmt}` - not used enough to stabilize
* `IntoCow` - conflicts with `Into` and may come back later
* `i32::{BITS, BYTES}` (and other integers) - not pulling their weight
* `DebugTuple::formatter` - will be removed
* `sync::Semaphore` - not used enough and confused with system semaphores

Closes #23284
cc #27709 (still lots more methods though)
Closes #27712
Closes #27722
Closes #27728
Closes #27735
Closes #27729
Closes #27755
Closes #27782
Closes #27798
2016-01-16 11:03:10 -08:00
Manish Goregaokar 6f4ede44de Rollup merge of #30801 - Amanieu:oom_print, r=alexcrichton
This adds the ability to override the default OOM behavior by setting a handler function. This is used by libstd to print a message when running out of memory instead of crashing with an obscure "illegal hardware instruction" error (at least on Linux).

Fixes #14674
2016-01-14 11:04:40 +05:30
Simon Martin c5da16012d Issue #30592: Restore build in --disable-jemalloc mode. 2016-01-13 21:15:00 +01:00
Amanieu d'Antras 757f57bb1e Add set_oom_handler and use it print a message when out of memory 2016-01-12 01:55:45 +00:00
Alex Crichton cd1848a1a6 Register new snapshots
Lots of cruft to remove!
2015-12-21 09:26:21 -08:00
Alex Crichton 464cdff102 std: Stabilize APIs for the 1.6 release
This commit is the standard API stabilization commit for the 1.6 release cycle.
The list of issues and APIs below have all been through their cycle-long FCP and
the libs team decisions are listed below

Stabilized APIs

* `Read::read_exact`
* `ErrorKind::UnexpectedEof` (renamed from `UnexpectedEOF`)
* libcore -- this was a bit of a nuanced stabilization, the crate itself is now
  marked as `#[stable]` and the methods appearing via traits for primitives like
  `char` and `str` are now also marked as stable. Note that the extension traits
  themeselves are marked as unstable as they're imported via the prelude. The
  `try!` macro was also moved from the standard library into libcore to have the
  same interface. Otherwise the functions all have copied stability from the
  standard library now.
* The `#![no_std]` attribute
* `fs::DirBuilder`
* `fs::DirBuilder::new`
* `fs::DirBuilder::recursive`
* `fs::DirBuilder::create`
* `os::unix::fs::DirBuilderExt`
* `os::unix::fs::DirBuilderExt::mode`
* `vec::Drain`
* `vec::Vec::drain`
* `string::Drain`
* `string::String::drain`
* `vec_deque::Drain`
* `vec_deque::VecDeque::drain`
* `collections::hash_map::Drain`
* `collections::hash_map::HashMap::drain`
* `collections::hash_set::Drain`
* `collections::hash_set::HashSet::drain`
* `collections::binary_heap::Drain`
* `collections::binary_heap::BinaryHeap::drain`
* `Vec::extend_from_slice` (renamed from `push_all`)
* `Mutex::get_mut`
* `Mutex::into_inner`
* `RwLock::get_mut`
* `RwLock::into_inner`
* `Iterator::min_by_key` (renamed from `min_by`)
* `Iterator::max_by_key` (renamed from `max_by`)

Deprecated APIs

* `ErrorKind::UnexpectedEOF` (renamed to `UnexpectedEof`)
* `OsString::from_bytes`
* `OsStr::to_cstring`
* `OsStr::to_bytes`
* `fs::walk_dir` and `fs::WalkDir`
* `path::Components::peek`
* `slice::bytes::MutableByteVector`
* `slice::bytes::copy_memory`
* `Vec::push_all` (renamed to `extend_from_slice`)
* `Duration::span`
* `IpAddr`
* `SocketAddr::ip`
* `Read::tee`
* `io::Tee`
* `Write::broadcast`
* `io::Broadcast`
* `Iterator::min_by` (renamed to `min_by_key`)
* `Iterator::max_by` (renamed to `max_by_key`)
* `net::lookup_addr`

New APIs (still unstable)

* `<[T]>::sort_by_key` (added to mirror `min_by_key`)

Closes #27585
Closes #27704
Closes #27707
Closes #27710
Closes #27711
Closes #27727
Closes #27740
Closes #27744
Closes #27799
Closes #27801
cc #27801 (doesn't close as `Chars` is still unstable)
Closes #28968
2015-12-05 15:09:44 -08:00
Vadim Petrochenkov be8ace8cac Remove all uses of #[staged_api] 2015-11-25 21:55:26 +03:00
Vadim Petrochenkov a613059e3f Rename #[deprecated] to #[rustc_deprecated] 2015-11-20 16:11:20 +03:00
Kevin Butler 7dbff09e57 liballoc: deny warnings in doctests 2015-11-12 05:15:08 +00:00
Alexis Beingessner e72c226bed expose drop_in_place as ptr::drop_in_place 2015-10-30 10:54:25 -04:00
Andrew Paseltiner d6bd8d8491 Add Shared pointer and have {Arc, Rc} use it
This change has two consequences:

1. It makes `Arc<T>` and `Rc<T>` covariant in `T`.

2. It causes the compiler to reject code that was unsound with respect
to dropck. See compile-fail/issue-29106.rs for an example of code that
no longer compiles. Because of this, this is a [breaking-change].

Fixes #29037.
Fixes #29106.
2015-10-16 18:35:31 -04:00