1.50.0 #
- Released on: 11 February, 2021
- Branched from master on: 25 December, 2020
Language #
- You can now use
const
values forx
in[x; N]
array expressions. This has been technically possible since 1.38.0, as it was unintentionally stabilized. - Assignments to
ManuallyDrop<T>
union fields are now considered safe.
Compiler #
- Added tier 3* support for the
armv5te-unknown-linux-uclibceabi
target. - Added tier 3 support for the
aarch64-apple-ios-macabi
target. - The
x86_64-unknown-freebsd
is now built with the full toolset. - Dropped support for all cloudabi targets.
* Refer to Rust’s [platform support page][platform-support-doc] for more information on Rust’s tiered platform support.
Libraries #
proc_macro::Punct
now implementsPartialEq<char>
.ops::{Index, IndexMut}
are now implemented for fixed sized arrays of any length.- On Unix platforms, the
std::fs::File
type now has a “niche” of-1
. This value cannot be a valid file descriptor, and now meansOption<File>
takes up the same amount of space asFile
.
Stabilized APIs #
bool::then
btree_map::Entry::or_insert_with_key
f32::clamp
f64::clamp
hash_map::Entry::or_insert_with_key
Ord::clamp
RefCell::take
slice::fill
UnsafeCell::get_mut
The following previously stable methods are now const
.
IpAddr::is_ipv4
IpAddr::is_ipv6
IpAddr::is_unspecified
IpAddr::is_loopback
IpAddr::is_multicast
Ipv4Addr::octets
Ipv4Addr::is_loopback
Ipv4Addr::is_private
Ipv4Addr::is_link_local
Ipv4Addr::is_multicast
Ipv4Addr::is_broadcast
Ipv4Addr::is_documentation
Ipv4Addr::to_ipv6_compatible
Ipv4Addr::to_ipv6_mapped
Ipv6Addr::segments
Ipv6Addr::is_unspecified
Ipv6Addr::is_loopback
Ipv6Addr::is_multicast
Ipv6Addr::to_ipv4
Layout::size
Layout::align
Layout::from_size_align
pow
for all integer types.checked_pow
for all integer types.saturating_pow
for all integer types.wrapping_pow
for all integer types.next_power_of_two
for all unsigned integer types.checked_next_power_of_two
for all unsigned integer types.
Cargo #
- Added the
[build.rustc-workspace-wrapper]
option. This option sets a wrapper to execute instead ofrustc
, for workspace members only. cargo:rerun-if-changed
will now, if provided a directory, scan the entire contents of that directory for changes.- Added the
--workspace
flag to thecargo update
command.
Misc #
- The search results tab and the help button are focusable with keyboard in rustdoc.
- Running tests will now print the total time taken to execute.
Compatibility Notes #
- The
compare_and_swap
method on atomics has been deprecated. It’s recommended to use thecompare_exchange
andcompare_exchange_weak
methods instead. - Changes in how
TokenStream
s are checked have fixed some cases where you could write unhygenicmacro_rules!
macros. #![test]
as an inner attribute is now considered unstable like other inner macro attributes, and reports an error by default through thesoft_unstable
lint.- Overriding a
forbid
lint at the same level that it was set is now a hard error. - You can no longer intercept
panic!
calls by supplying your own macro. It’s recommended to use the#[panic_handler]
attribute to provide your own implementation. - Semi-colons after item statements (e.g.
struct Foo {};
) now produce a warning.