This commit performs a second pass over the `std::string` module, performing the
following actions:
* The name `std::string` is now stable.
* The `String::from_utf8` function is now stable after having been altered to
return a new `FromUtf8Error` structure. The `FromUtf8Error` structure is now
stable as well as its `into_bytes` and `utf8_error` methods.
* The `String::from_utf8_lossy` function is now stable.
* The `String::from_chars` method is now deprecated in favor of `.collect()`
* The `String::from_raw_parts` method is now stable
* The `String::from_str` function remains experimental
* The `String::from_raw_buf` function remains experimental
* The `String::from_raw_buf_len` function remains experimental
* The `String::from_utf8_unchecked` function is now stable
* The `String::from_char` function is now deprecated in favor of
`repeat(c).take(n).collect()`
* The `String::grow` function is now deprecated in favor of
`.extend(repeat(c).take(n)`
* The `String::capacity` method is now stable
* The `String::reserve` method is now stable
* The `String::reserve_exact` method is now stable
* The `String::shrink_to_fit` method is now stable
* The `String::pop` method is now stable
* The `String::as_mut_vec` method is now stable
* The `String::is_empty` method is now stable
* The `IntoString` trait is now deprecated (there are no implementors)
* The `String::truncate` method is now stable
* The `String::insert` method is now stable
* The `String::remove` method is now stable
* The `String::push` method is now stable
* The `String::push_str` method is now stable
* The `String::from_utf16` function is now stable after its error type has now
become an opaque structure to carry more semantic information in the future.
A number of these changes are breaking changes, but the migrations should be
fairly straightforward on a case-by-case basis (outlined above where possible).
[breaking-change]
Since runtime is removed, rust has no tasks anymore and everything is moving
from being task-* to thread-*. Let’s rename TaskRng as well!
This is a breaking change. If a breaking change for consistency is not desired, feel free to close.
The first six commits are from an earlier PR (#19858) and have already been reviewed. This PR makes an awful hack in the compiler to accommodate slices both natively and in the index a range form. After a snapshot we can hopefully add the new Index impls and then we can remove these awful hacks.
r? @nikomatsakis (or anyone who knows the compiler, really)
This commit performs a second pass for stabilization over the `std::ptr` module.
The specific actions taken were:
* The `RawPtr` trait was renamed to `PtrExt`
* The `RawMutPtr` trait was renamed to `MutPtrExt`
* The module name `ptr` is now stable.
* These functions were all marked `#[stable]` with no modification:
* `null`
* `null_mut`
* `swap`
* `replace`
* `read`
* `write`
* `PtrExt::is_null`
* `PtrExt::offset`
* These functions remain unstable:
* `as_ref`, `as_mut` - the return value of an `Option` is not fully expressive
as null isn't the only bad value, and it's unclear
whether we want to commit to these functions at this
time. The reference/lifetime semantics as written are
also problematic in how they encourage arbitrary
lifetimes.
* `zero_memory` - This function is currently not used at all in the
distribution, and in general it plays a broader role in the
"working with unsafe pointers" story. This story is not yet
fully developed, so at this time the function remains
unstable for now.
* `read_and_zero` - This function remains unstable for largely the same
reasons as `zero_memory`.
* These functions are now all deprecated:
* `PtrExt::null` - call `ptr::null` or `ptr::null_mut` instead.
* `PtrExt::to_uint` - use an `as` expression instead.
* `PtrExt::is_not_null` - use `!p.is_null()` instead.
This commit performs a second pass over the `std::string` module, performing the
following actions:
* The name `std::string` is now stable.
* The `String::from_utf8` function is now stable after having been altered to
return a new `FromUtf8Error` structure. The `FromUtf8Error` structure is now
stable as well as its `into_bytes` and `utf8_error` methods.
* The `String::from_utf8_lossy` function is now stable.
* The `String::from_chars` method is now deprecated in favor of `.collect()`
* The `String::from_raw_parts` method is now stable
* The `String::from_str` function remains experimental
* The `String::from_raw_buf` function remains experimental
* The `String::from_raw_buf_len` function remains experimental
* The `String::from_utf8_unchecked` function is now stable
* The `String::from_char` function is now deprecated in favor of
`repeat(c).take(n).collect()`
* The `String::grow` function is now deprecated in favor of
`.extend(repeat(c).take(n)`
* The `String::capacity` method is now stable
* The `String::reserve` method is now stable
* The `String::reserve_exact` method is now stable
* The `String::shrink_to_fit` method is now stable
* The `String::pop` method is now stable
* The `String::as_mut_vec` method is now stable
* The `String::is_empty` method is now stable
* The `IntoString` trait is now deprecated (there are no implementors)
* The `String::truncate` method is now stable
* The `String::insert` method is now stable
* The `String::remove` method is now stable
* The `String::push` method is now stable
* The `String::push_str` method is now stable
* The `String::from_utf16` function is now stable after its error type has now
become an opaque structure to carry more semantic information in the future.
A number of these changes are breaking changes, but the migrations should be
fairly straightforward on a case-by-case basis (outlined above where possible).
[breaking-change]
This commit is a second pass stabilization for the `std::comm` module,
performing the following actions:
* The entire `std::comm` module was moved under `std::sync::mpsc`. This movement
reflects that channels are just yet another synchronization primitive, and
they don't necessarily deserve a special place outside of the other
concurrency primitives that the standard library offers.
* The `send` and `recv` methods have all been removed.
* The `send_opt` and `recv_opt` methods have been renamed to `send` and `recv`.
This means that all send/receive operations return a `Result` now indicating
whether the operation was successful or not.
* The error type of `send` is now a `SendError` to implement a custom error
message and allow for `unwrap()`. The error type contains an `into_inner`
method to extract the value.
* The error type of `recv` is now `RecvError` for the same reasons as `send`.
* The `TryRecvError` and `TrySendError` types have had public reexports removed
of their variants and the variant names have been tweaked with enum
namespacing rules.
* The `Messages` iterator is renamed to `Iter`
This functionality is now all `#[stable]`:
* `Sender`
* `SyncSender`
* `Receiver`
* `std::sync::mpsc`
* `channel`
* `sync_channel`
* `Iter`
* `Sender::send`
* `Sender::clone`
* `SyncSender::send`
* `SyncSender::try_send`
* `SyncSender::clone`
* `Receiver::recv`
* `Receiver::try_recv`
* `Receiver::iter`
* `SendError`
* `RecvError`
* `TrySendError::{mod, Full, Disconnected}`
* `TryRecvError::{mod, Empty, Disconnected}`
* `SendError::into_inner`
* `TrySendError::into_inner`
This is a breaking change due to the modification of where this module is
located, as well as the changing of the semantics of `send` and `recv`. Most
programs just need to rename imports of `std::comm` to `std::sync::mpsc` and
add calls to `unwrap` after a send or a receive operation.
[breaking-change]
This stabilizes most methods on `&str` working with patterns in a way that is forwards-compatible with a generic string pattern matching API:
- Methods that are using the primary name for their operation are marked as `#[stable]`, as they can be upgraded to a full `Pattern` API later without existing code breaking. Example: `contains(&str)`
- Methods that are using a more specific name in order to not clash with the primary one are marked as `#[unstable]`, as they will likely be removed once their functionality is merged into the primary one. Example: `contains_char<C: CharEq>(C)`
- The method docs got changed to consistently refer to the pattern types as a pattern.
- Methods whose names do not match in the context of the more generic API got renamed. Example: `trim_chars -> trim_matches`
Additionally, all methods returning iterators got changed to return unique new types with changed names in accordance with the new naming guidelines.
See also https://github.com/rust-lang/rfcs/pull/528
Due to some deprecations and type changes, this is a
[breaking-change]
This commit is an implementation of [RFC 503][rfc] which is a stabilization
story for the prelude. Most of the RFC was directly applied, removing reexports.
Some reexports are kept around, however:
* `range` remains until range syntax has landed to reduce churn.
* `Path` and `GenericPath` remain until path reform lands. This is done to
prevent many imports of `GenericPath` which will soon be removed.
* All `io` traits remain until I/O reform lands so imports can be rewritten all
at once to `std::io::prelude::*`.
This is a breaking change because many prelude reexports have been removed, and
the RFC can be consulted for the exact list of removed reexports, as well as to
find the locations of where to import them.
[rfc]: https://github.com/rust-lang/rfcs/blob/master/text/0503-prelude-stabilization.md
[breaking-change]
Closes#20068
This extends the nullable enum opt to traverse beyond just the first level to find possible fields to use as the discriminant. So now, it'll work through structs, tuples, and fixed sized arrays. This also introduces a new lang item, NonZero, that you can use to wrap raw pointers or integral types to indicate to rustc that the underlying value is known to never be 0/NULL. We then use this in Vec, Rc and Arc to have them also benefit from the nullable enum opt.
As per https://github.com/rust-lang/rfcs/pull/499 NonZero is not exposed via the `libstd` facade.
```
x86_64 Linux:
T Option<T> (Before) Option<T> (After)
----------------------------------------------------------------------------------
Vec<int> 24 32 24
String 24 32 24
Rc<int> 8 16 8
Arc<int> 8 16 8
[Box<int>, ..2] 16 24 16
(String, uint) 32 40 32
```
Fixes#19419.
Fixes#13194.
Fixes#9378.
Fixes#7576.
This PR deprecates the `DList::ListInsertion` trait, in accordance with rust-lang/rfcs#509. The functions which were previously part of the ListInsertion impl for `DList::IterMut` have been moved to be inherent methods on the iterator itself, and appropriate doctests have been added.
Since runtime is removed, rust has no tasks anymore and everything is moving
from being task-* to thread-*. Let’s rename TaskRng as well!
* Rename TaskRng to ThreadRng
* Rename task_rng to thread_rng
[breaking-change]
More work on opt-in built in traits. `Send` and `Sync` are not opt-in, `OwnedPtr` renamed to `UniquePtr` and the `Send` and `Sync` traits are now unsafe.
NOTE: This likely needs to be rebased on top of the yet-to-land snapshot.
r? @nikomatsakis
cc #13231
This breaks code that looks like this:
let x = foo as bar << 13;
Change such code to look like this:
let x = (foo as bar) << 13;
Closes#17362.
[breaking-change]
This is an updated version of #19711. The merge and subsequent rebase on that branch were more trouble than they were worth, so I am just resubmitting the relevant change here.
If this PR is accepted, then #19711 can be closed.
/cc @Gankro
This pull request:
*Renames `BinaryHeap::top` to `BinaryHeap::peek`
*Stabilizes `front/back/front_mut/back_mut` in `DList` and `RingBuf`
*Stabilizes `swap` in `RingBuf`
in accordance with rust-lang/rfcs#509.
Note that this PR does not address `Bitv::{get,set}` or HashMap's iterators, nor does it move `std::vec` to `std::collections::vec`, all of which still need to be done.
Because of the method renaming, this is a [breaking-change].
This commit starts out by consolidating all `str` extension traits into one
`StrExt` trait to be included in the prelude. This means that
`UnicodeStrPrelude`, `StrPrelude`, and `StrAllocating` have all been merged into
one `StrExt` exported by the standard library. Some functionality is currently
duplicated with the `StrExt` present in libcore.
This commit also currently avoids any methods which require any form of pattern
to operate. These functions will be stabilized via a separate RFC.
Next, stability of methods and structures are as follows:
Stable
* from_utf8_unchecked
* CowString - after moving to std::string
* StrExt::as_bytes
* StrExt::as_ptr
* StrExt::bytes/Bytes - also made a struct instead of a typedef
* StrExt::char_indices/CharIndices - CharOffsets was renamed
* StrExt::chars/Chars
* StrExt::is_empty
* StrExt::len
* StrExt::lines/Lines
* StrExt::lines_any/LinesAny
* StrExt::slice_unchecked
* StrExt::trim
* StrExt::trim_left
* StrExt::trim_right
* StrExt::words/Words - also made a struct instead of a typedef
Unstable
* from_utf8 - the error type was changed to a `Result`, but the error type has
yet to prove itself
* from_c_str - this function will be handled by the c_str RFC
* FromStr - this trait will have an associated error type eventually
* StrExt::escape_default - needs iterators at least, unsure if it should make
the cut
* StrExt::escape_unicode - needs iterators at least, unsure if it should make
the cut
* StrExt::slice_chars - this function has yet to prove itself
* StrExt::slice_shift_char - awaiting conventions about slicing and shifting
* StrExt::graphemes/Graphemes - this functionality may only be in libunicode
* StrExt::grapheme_indices/GraphemeIndices - this functionality may only be in
libunicode
* StrExt::width - this functionality may only be in libunicode
* StrExt::utf16_units - this functionality may only be in libunicode
* StrExt::nfd_chars - this functionality may only be in libunicode
* StrExt::nfkd_chars - this functionality may only be in libunicode
* StrExt::nfc_chars - this functionality may only be in libunicode
* StrExt::nfkc_chars - this functionality may only be in libunicode
* StrExt::is_char_boundary - naming is uncertain with container conventions
* StrExt::char_range_at - naming is uncertain with container conventions
* StrExt::char_range_at_reverse - naming is uncertain with container conventions
* StrExt::char_at - naming is uncertain with container conventions
* StrExt::char_at_reverse - naming is uncertain with container conventions
* StrVector::concat - this functionality may be replaced with iterators, but
it's not certain at this time
* StrVector::connect - as with concat, may be deprecated in favor of iterators
Deprecated
* StrAllocating and UnicodeStrPrelude have been merged into StrExit
* eq_slice - compiler implementation detail
* from_str - use the inherent parse() method
* is_utf8 - call from_utf8 instead
* replace - call the method instead
* truncate_utf16_at_nul - this is an implementation detail of windows and does
not need to be exposed.
* utf8_char_width - moved to libunicode
* utf16_items - moved to libunicode
* is_utf16 - moved to libunicode
* Utf16Items - moved to libunicode
* Utf16Item - moved to libunicode
* Utf16Encoder - moved to libunicode
* AnyLines - renamed to LinesAny and made a struct
* SendStr - use CowString<'static> instead
* str::raw - all functionality is deprecated
* StrExt::into_string - call to_string() instead
* StrExt::repeat - use iterators instead
* StrExt::char_len - use .chars().count() instead
* StrExt::is_alphanumeric - use .chars().all(..)
* StrExt::is_whitespace - use .chars().all(..)
Pending deprecation -- while slicing syntax is being worked out, these methods
are all #[unstable]
* Str - while currently used for generic programming, this trait will be
replaced with one of [], deref coercions, or a generic conversion trait.
* StrExt::slice - use slicing syntax instead
* StrExt::slice_to - use slicing syntax instead
* StrExt::slice_from - use slicing syntax instead
* StrExt::lev_distance - deprecated with no replacement
Awaiting stabilization due to patterns and/or matching
* StrExt::contains
* StrExt::contains_char
* StrExt::split
* StrExt::splitn
* StrExt::split_terminator
* StrExt::rsplitn
* StrExt::match_indices
* StrExt::split_str
* StrExt::starts_with
* StrExt::ends_with
* StrExt::trim_chars
* StrExt::trim_left_chars
* StrExt::trim_right_chars
* StrExt::find
* StrExt::rfind
* StrExt::find_str
* StrExt::subslice_offset
Part of #18424
This commit changes the semantics of `reserve` and `capacity` for Bitv and BitvSet to match conventions. It also introduces the notion of `reserve_index` and `reserve_index_exact` for collections with maximum-index-based capacity semantics.
Deprecates free function constructors in favour of functions on Bitv itself.
Changes `Bitv::pop` to return an Option rather than panicking.
Deprecates and renames several methods in favour of conventions.
Marks several blessed methods as unstable.
This commit also substantially refactors Bitv and BitvSet's implementations. The new implementation is simpler, cleaner, better documented, and more robust against overflows. It also reduces coupling between Bitv and BitvSet. Tests have been seperated into seperate submodules.
Fixes#16958
[breaking-change]
post-unboxed-closure-conversion. This requires a fair amount of
annoying coercions because all the `map` etc types are defined
generically over the `F`, so the automatic coercions don't propagate;
this is compounded by the need to use `let` and not `as` due to
stage0. That said, this pattern is to a large extent temporary and
unusual.
This commit:
*Renames `BinaryHeap::top` to `BinaryHeap::peek`
*Stabilizes `front/back/front_mut/back_mut` in `DList` and `RingBuf`
*Stabilizes `swap` in `RingBuf`
Because of the method renaming, this is a [breaking-change].
This commit starts out by consolidating all `str` extension traits into one
`StrExt` trait to be included in the prelude. This means that
`UnicodeStrPrelude`, `StrPrelude`, and `StrAllocating` have all been merged into
one `StrExt` exported by the standard library. Some functionality is currently
duplicated with the `StrExt` present in libcore.
This commit also currently avoids any methods which require any form of pattern
to operate. These functions will be stabilized via a separate RFC.
Next, stability of methods and structures are as follows:
Stable
* from_utf8_unchecked
* CowString - after moving to std::string
* StrExt::as_bytes
* StrExt::as_ptr
* StrExt::bytes/Bytes - also made a struct instead of a typedef
* StrExt::char_indices/CharIndices - CharOffsets was renamed
* StrExt::chars/Chars
* StrExt::is_empty
* StrExt::len
* StrExt::lines/Lines
* StrExt::lines_any/LinesAny
* StrExt::slice_unchecked
* StrExt::trim
* StrExt::trim_left
* StrExt::trim_right
* StrExt::words/Words - also made a struct instead of a typedef
Unstable
* from_utf8 - the error type was changed to a `Result`, but the error type has
yet to prove itself
* from_c_str - this function will be handled by the c_str RFC
* FromStr - this trait will have an associated error type eventually
* StrExt::escape_default - needs iterators at least, unsure if it should make
the cut
* StrExt::escape_unicode - needs iterators at least, unsure if it should make
the cut
* StrExt::slice_chars - this function has yet to prove itself
* StrExt::slice_shift_char - awaiting conventions about slicing and shifting
* StrExt::graphemes/Graphemes - this functionality may only be in libunicode
* StrExt::grapheme_indices/GraphemeIndices - this functionality may only be in
libunicode
* StrExt::width - this functionality may only be in libunicode
* StrExt::utf16_units - this functionality may only be in libunicode
* StrExt::nfd_chars - this functionality may only be in libunicode
* StrExt::nfkd_chars - this functionality may only be in libunicode
* StrExt::nfc_chars - this functionality may only be in libunicode
* StrExt::nfkc_chars - this functionality may only be in libunicode
* StrExt::is_char_boundary - naming is uncertain with container conventions
* StrExt::char_range_at - naming is uncertain with container conventions
* StrExt::char_range_at_reverse - naming is uncertain with container conventions
* StrExt::char_at - naming is uncertain with container conventions
* StrExt::char_at_reverse - naming is uncertain with container conventions
* StrVector::concat - this functionality may be replaced with iterators, but
it's not certain at this time
* StrVector::connect - as with concat, may be deprecated in favor of iterators
Deprecated
* StrAllocating and UnicodeStrPrelude have been merged into StrExit
* eq_slice - compiler implementation detail
* from_str - use the inherent parse() method
* is_utf8 - call from_utf8 instead
* replace - call the method instead
* truncate_utf16_at_nul - this is an implementation detail of windows and does
not need to be exposed.
* utf8_char_width - moved to libunicode
* utf16_items - moved to libunicode
* is_utf16 - moved to libunicode
* Utf16Items - moved to libunicode
* Utf16Item - moved to libunicode
* Utf16Encoder - moved to libunicode
* AnyLines - renamed to LinesAny and made a struct
* SendStr - use CowString<'static> instead
* str::raw - all functionality is deprecated
* StrExt::into_string - call to_string() instead
* StrExt::repeat - use iterators instead
* StrExt::char_len - use .chars().count() instead
* StrExt::is_alphanumeric - use .chars().all(..)
* StrExt::is_whitespace - use .chars().all(..)
Pending deprecation -- while slicing syntax is being worked out, these methods
are all #[unstable]
* Str - while currently used for generic programming, this trait will be
replaced with one of [], deref coercions, or a generic conversion trait.
* StrExt::slice - use slicing syntax instead
* StrExt::slice_to - use slicing syntax instead
* StrExt::slice_from - use slicing syntax instead
* StrExt::lev_distance - deprecated with no replacement
Awaiting stabilization due to patterns and/or matching
* StrExt::contains
* StrExt::contains_char
* StrExt::split
* StrExt::splitn
* StrExt::split_terminator
* StrExt::rsplitn
* StrExt::match_indices
* StrExt::split_str
* StrExt::starts_with
* StrExt::ends_with
* StrExt::trim_chars
* StrExt::trim_left_chars
* StrExt::trim_right_chars
* StrExt::find
* StrExt::rfind
* StrExt::find_str
* StrExt::subslice_offset
`String::push(&mut self, ch: char)` currently has a single code path that calls `Char::encode_utf8`. This adds a fast path for ASCII `char`s, which are represented as a single byte in UTF-8.
Benchmarks of stage1 libcollections at the intermediate commit show that the fast path very significantly improves the performance of repeatedly pushing an ASCII `char`, but does not significantly affect the performance for a non-ASCII `char` (where the fast path is not taken).
```
bench_push_char_one_byte 59552 ns/iter (+/- 2132) = 167 MB/s
bench_push_char_one_byte_with_fast_path 6563 ns/iter (+/- 658) = 1523 MB/s
bench_push_char_two_bytes 71520 ns/iter (+/- 3541) = 279 MB/s
bench_push_char_two_bytes_with_slow_path 71452 ns/iter (+/- 4202) = 279 MB/s
bench_push_str_one_byte 38910 ns/iter (+/- 2477) = 257 MB/s
```
A benchmark of pushing a one-byte-long `&str` is added for comparison, but its performance [has varied a lot lately](https://github.com/rust-lang/rust/pull/19640#issuecomment-67741561). (When the input is fixed, `s.push_str("x")` could be used just as well as `s.push('x')`.)
This patch marks `clone` stable, as well as the `Clone` trait, but
leaves `clone_from` unstable. The latter will be decided by the beta.
The patch also marks most manual implementations of `Clone` as stable,
except where the APIs are otherwise deprecated or where there is
uncertainty about providing `Clone`.
r? @alexcrichton
TL;DR I wrongly implemented these two ops, namely `"prefix" + "suffix".to_string()` gives back `"suffixprefix"`. Let's remove them.
The correct implementation of these operations (`lhs.clone().push_str(rhs.as_slice())`) is really wasteful, because the lhs has to be cloned and the rhs gets moved/consumed just to be dropped (no buffer reuse). For this reason, I'd prefer to drop the implementation instead of fixing it. This leaves us with the fact that you'll be able to do `String + &str` but not `&str + String`, which may be unexpected.
r? @aturon
Closes#19952
It is useful to move all the elements out of a hashmap without deallocating
the underlying buffer. It came up in IRC, and this patch implements it as
`drain`.
r? @Gankro
cc: @frankmcsherry
`String::push(&mut self, ch: char)` currently has a single code path
that calls `Char::encode_utf8`.
Perhaps it could be faster for ASCII `char`s, which are represented as
a single byte in UTF-8.
This commit leaves the method unchanged,
adds a copy of it with the fast path,
and adds benchmarks to compare them.
Results show that the fast path very significantly improves the performance
of repeatedly pushing an ASCII `char`,
but does not significantly affect the performance for a non-ASCII `char`
(where the fast path is not taken).
Output of `make check-stage1-collections NO_REBUILD=1 PLEASE_BENCH=1 TESTNAME=string::tests::bench_push`
```
test string::tests::bench_push_char_one_byte ... bench: 59552 ns/iter (+/- 2132) = 167 MB/s
test string::tests::bench_push_char_one_byte_with_fast_path ... bench: 6563 ns/iter (+/- 658) = 1523 MB/s
test string::tests::bench_push_char_two_bytes ... bench: 71520 ns/iter (+/- 3541) = 279 MB/s
test string::tests::bench_push_char_two_bytes_with_slow_path ... bench: 71452 ns/iter (+/- 4202) = 279 MB/s
test string::tests::bench_push_str ... bench: 24 ns/iter (+/- 2)
test string::tests::bench_push_str_one_byte ... bench: 38910 ns/iter (+/- 2477) = 257 MB/s
```
A benchmark of pushing a one-byte-long `&str` is added for comparison,
but its performance [has varied a lot lately](
https://github.com/rust-lang/rust/pull/19640#issuecomment-67741561).
(When the input is fixed, `s.push_str("x")` could be used
instead of `s.push('x')`.)
The old logic would be ok with *either* 0 or all 1s in the last word,
because it didn't compute a proper mask for the case where nbits is an
exact multiple of u32::BITS.
Add mask_for_bits() to compute this properly, and use it in all(). Add
all/none assertions to most of the tests. Note in particular, the all-zero
bitv in test_32_elements() was incorrectly all()==true before this patch.
- Fix typos on Blocks and MutBlocks.
- Use slice_to_mut() for creating blocks_mut().
- Deref the block parameter in get().
- Access nbits separately from mutating set in pop().
Part of #18424
This commit changes the semantics of `reserve` and `capacity` for Bitv and BitvSet to match conventions. It also introduces the notion of `reserve_index` and `reserve_index_exact` for collections with maximum-index-based capacity semantics.
Deprecates free function constructors in favour of functions on Bitv itself.
Changes `Bitv::pop` to return an Option rather than panicking.
Deprecates and renames several methods in favour of conventions.
Marks several blessed methods as unstable.
This commit also substantially refactors Bitv and BitvSet's implementations. The new implementation is simpler, cleaner, better documented, and more robust against overflows. It also reduces coupling between Bitv and BitvSet. Tests have been seperated into seperate submodules.
Fixes#16958
[breaking-change]
This patch marks `clone` stable, as well as the `Clone` trait, but
leaves `clone_from` unstable. The latter will be decided by the beta.
The patch also marks most manual implementations of `Clone` as stable,
except where the APIs are otherwise deprecated or where there is
uncertainty about providing `Clone`.
The `is_power_of_two()` method of the `UnsignedInt` trait currently returns `true` for `self == 0`. Zero is not a power of two, assuming an integral exponent `k >= 0`. I've therefore moved this functionality to the new method `is_power_of_two_or_zero()` and reformed `is_power_of_two()` to return false for `self == 0`.
To illustrate the usefulness of the existence of both functions, consider `HashMap`. Its capacity must be zero or a power of two; conversely, it also requires a (non-zero) power of two for key and val alignment.
Also, added a small amount of documentation regarding #18604.
Rewrite how the HRTB algorithm matches impls against obligations. Instead of impls providing higher-ranked trait-references, impls now once again only have early-bound regions. The skolemization checks are thus moved out into trait matching itself. This allows to implement "perfect forwarding" impls like those described in #19730. This PR builds on a previous PR that was already reviewed by @pnkfelix.
r? @pnkfelix
Fixes#19730
lifetimes. This currently causes an ICE; it should (ideally) work, but
failing that at least give a structured error. For the purposes of
this PR, though, workaround is fine.
This commit is part of a series that introduces a `std::thread` API to
replace `std::task`.
In the new API, `spawn` returns a `JoinGuard`, which by default will
join the spawned thread when dropped. It can also be used to join
explicitly at any time, returning the thread's result. Alternatively,
the spawned thread can be explicitly detached (so no join takes place).
As part of this change, Rust processes now terminate when the main
thread exits, even if other detached threads are still running, moving
Rust closer to standard threading models. This new behavior may break code
that was relying on the previously implicit join-all.
In addition to the above, the new thread API also offers some built-in
support for building blocking abstractions in user space; see the module
doc for details.
Closes#18000
[breaking-change]
This commit merges the `rustrt` crate into `std`, undoing part of the
facade. This merger continues the paring down of the runtime system.
Code relying on the public API of `rustrt` will break; some of this API
is now available through `std::rt`, but is likely to change and/or be
removed very soon.
[breaking-change]
It is useful to move all the elements out of some collections without
deallocating the underlying buffer. It came up in IRC, and this patch
implements it as `drain`. This has been discussed as part of RFC 509.
r? @Gankro
cc: @frankmcsherry
followed by a semicolon.
This allows code like `vec![1i, 2, 3].len();` to work.
This breaks code that uses macros as statements without putting
semicolons after them, such as:
fn main() {
...
assert!(a == b)
assert!(c == d)
println(...);
}
It also breaks code that uses macros as items without semicolons:
local_data_key!(foo)
fn main() {
println("hello world")
}
Add semicolons to fix this code. Those two examples can be fixed as
follows:
fn main() {
...
assert!(a == b);
assert!(c == d);
println(...);
}
local_data_key!(foo);
fn main() {
println("hello world")
}
RFC #378.
Closes#18635.
[breaking-change]
In US english, "that" is used in restrictive clauses in place of
"which", and often affects the meaning of sentences.
In UK english and many dialects, no distinction is
made.
While Rust devs want to avoid unproductive pedanticism, it is worth at
least being uniform in documentation such as:
http://doc.rust-lang.org/std/iter/index.html
and also in cases where correct usage of US english clarifies the
sentence.
Includes a fix for a small mistake in `fn insert` which is caught by test_insert for len=15, but not len=7.
Part of #18424
r? @Gankro @csherratt @huonw
Using a type alias for iterator implementations is fragile since this exposes the implementation to users of the iterator, and any changes could break existing code.
This PR changes the iterators of `BTreeMap`, `BTreeSet`, `HashMap`, and `HashSet` to use proper new types, rather than type aliases. However, since it is fair-game to treat a type-alias as the aliased type, this is a:
[breaking-change].
Using a type alias for iterator implementations is fragile since this
exposes the implementation to users of the iterator, and any changes
could break existing code.
This commit changes the iterators of `VecMap` to use
proper new types, rather than type aliases. However, since it is
fair-game to treat a type-alias as the aliased type, this is a:
[breaking-change].
per rfc 459
cc https://github.com/rust-lang/rust/issues/19390
One question is: should we start by warning, and only switch to hard error later? I think we discussed something like this in the meeting.
r? @alexcrichton
This commit performs a second pass stabilization of the `std::default` module.
The module was already marked `#[stable]`, and the inheritance of `#[stable]`
was removed since this attribute was applied. This commit adds the `#[stable]`
attribute to the trait definition and one method name, along with all
implementations found in the standard distribution.
This commit collapses the various prelude traits for slices into just one trait:
* SlicePrelude/SliceAllocPrelude => SliceExt
* CloneSlicePrelude/CloneSliceAllocPrelude => CloneSliceExt
* OrdSlicePrelude/OrdSliceAllocPrelude => OrdSliceExt
* PartialEqSlicePrelude => PartialEqSliceExt
Using a type alias for iterator implementations is fragile since this
exposes the implementation to users of the iterator, and any changes
could break existing code.
This commit changes the iterators of `BTreeSet` to use
proper new types, rather than type aliases. However, since it is
fair-game to treat a type-alias as the aliased type, this is a:
[breaking-change].
Using a type alias for iterator implementations is fragile since this
exposes the implementation to users of the iterator, and any changes
could break existing code.
This commit changes the keys and values iterators of `BTreeMap` to use
proper new types, rather than type aliases. However, since it is
fair-game to treat a type-alias as the aliased type, this is a:
[breaking-change].
- The following operator traits now take their arguments by value: `Add`, `Sub`, `Mul`, `Div`, `Rem`, `BitAnd`, `BitOr`, `BitXor`, `Shl`, `Shr`. This breaks all existing implementations of these traits.
- The binary operation `a OP b` now "desugars" to `OpTrait::op_method(a, b)` and consumes both arguments.
- `String` and `Vec` addition have been changed to reuse the LHS owned value, and to avoid internal cloning. Only the following asymmetric operations are available: `String + &str` and `Vec<T> + &[T]`, which are now a short-hand for the "append" operation.
[breaking-change]
---
This passes `make check` locally. I haven't touch the unary operators in this PR, but converting them to by value should be very similar to this PR. I can work on them after this gets the thumbs up.
@nikomatsakis r? the compiler changes
@aturon r? the library changes. I think the only controversial bit is the semantic change of the `Vec`/`String` `Add` implementation.
cc #19148
In US english, "that" is used in restrictive clauses in place of
"which", and often affects the meaning of sentences.
In UK english and many dialects, no distinction is
made.
While Rust devs want to avoid unproductive pedanticism, it is worth at
least being uniform in documentation such as:
http://doc.rust-lang.org/std/iter/index.html
and also in cases where correct usage of US english clarifies the
sentence.
This commit collapses the various prelude traits for slices into just one trait:
* SlicePrelude/SliceAllocPrelude => SliceExt
* CloneSlicePrelude/CloneSliceAllocPrelude => CloneSliceExt
* OrdSlicePrelude/OrdSliceAllocPrelude => OrdSliceExt
* PartialEqSlicePrelude => PartialEqSliceExt
Using a type alias for iterator implementations is fragile since this
exposes the implementation to users of the iterator, and any changes
could break existing code.
This commit changes the iterators of `VecMap` to use
proper new types, rather than type aliases. However, since it is
fair-game to treat a type-alias as the aliased type, this is a:
[breaking-change].
This is a first pass at insert on RingBuf. I tried to keep it as simple as possible. I'm not sure of the performance implications of doing one copy vs. copying multiple times but moving a smaller amount of memory. I chose to stick with one copy, even if the amount of memory I have to move is larger.
I believe this is part of #18424
@Gankro mentioned this was missing.
I am trying to add an implementation of `bitor` for `BTreeSet`. I think I am most of the way there, but I am going to need some guidance to take it all the way.
When I run `make check`, I get:
```
error: cannot move out of dereference of `&`-pointer
self.union(_rhs).map(|&i| i).collect::<BTreeSet<T>>()
^~
```
I'd appreciate any nudges in the right direction. If I can figure this one out, I am sure I will be able to implement `bitand`, `bitxor`, and `sub` as well.
/cc @Gankro
---
**Update**
I have added implementations for `BitOr`, `BitAnd`, `BitXor`, and `Sub` for `BTreeSet`.
Add initial attempt at implementing BitOr for BTreeSet.
Update the implementation of the bitor operator for BTreeSets.
`make check` ran fine through this.
Add implementations for BitAnd, BitXor, and Sub as well.
Remove the FIXME comment and add unstable flags.
Add doctests for the bitop functions.
- Introduce a named type for the return type of `VecMap::move_iter`
- Rename all type parameters to `V` for "Value".
- Remove unnecessary call to an `Option::unwrap`, use pattern matching instead.
- Remove incorrect `Hash` implementation which took the `VecMap`'s capacity
into account.
This is a [breaking-change], however whoever used the `Hash` implementation
relied on an incorrect implementation.
Strings iterate to both char and &str, so it is natural it can also be extended or collected from an iterator of &str.
Apart from the trait implementations, `Extend<char>` is updated to use the iterator size hint, and the test added tests both the char and the &str versions of Extend and FromIterator.
I'm interested in including doctests for `BTreeMap`'s `iter_mut` and `into_iter` methods in this PR as well, but I am not sure of the best way to demonstrate/test what they do for the doctests.
- Introduce a named type for the return type of `VecMap::move_iter`
- Rename all type parameters to `V` for "Value".
- Remove unnecessary call to an `Option::unwrap`, use pattern matching instead.
- Remove incorrect `Hash` implementation which took the `VecMap`'s capacity
into account.
This is a [breaking-change], however whoever used the `Hash` implementation
relied on an incorrect implementation.
Change Example to Examples.
Add a doctest that better demonstrates the utility of as_string.
Update the doctest example to use String instead of &String.
This change makes the compiler no longer infer whether types (structures
and enumerations) implement the `Copy` trait (and thus are implicitly
copyable). Rather, you must implement `Copy` yourself via `impl Copy for
MyType {}`.
A new warning has been added, `missing_copy_implementations`, to warn
you if a non-generic public type has been added that could have
implemented `Copy` but didn't.
For convenience, you may *temporarily* opt out of this behavior by using
`#![feature(opt_out_copy)]`. Note though that this feature gate will never be
accepted and will be removed by the time that 1.0 is released, so you should
transition your code away from using it.
This breaks code like:
#[deriving(Show)]
struct Point2D {
x: int,
y: int,
}
fn main() {
let mypoint = Point2D {
x: 1,
y: 1,
};
let otherpoint = mypoint;
println!("{}{}", mypoint, otherpoint);
}
Change this code to:
#[deriving(Show)]
struct Point2D {
x: int,
y: int,
}
impl Copy for Point2D {}
fn main() {
let mypoint = Point2D {
x: 1,
y: 1,
};
let otherpoint = mypoint;
println!("{}{}", mypoint, otherpoint);
}
This is the backwards-incompatible part of #13231.
Part of RFC #3.
[breaking-change]
(I don't understand why this works, and so I don't quite trust this yet. I'm pushing it up to see if anyone else can replicate this performance increase)
Somehow llvm is able to optimize this version of Vec::reserve into dramatically faster than the old version. In micro-benchmarks this was 2-10 times faster. It also reduce my Rust compile time from 41 minutes to 27 minutes.
Closes#19281.
Now that we have an overloaded comparison (`==`) operator, and that `Vec`/`String` deref to `[T]`/`str` on method calls, many `as_slice()`/`as_mut_slice()`/`to_string()` calls have become redundant. This patch removes them. These were the most common patterns:
- `assert_eq(test_output.as_slice(), "ground truth")` -> `assert_eq(test_output, "ground truth")`
- `assert_eq(test_output, "ground truth".to_string())` -> `assert_eq(test_output, "ground truth")`
- `vec.as_mut_slice().sort()` -> `vec.sort()`
- `vec.as_slice().slice(from, to)` -> `vec.slice(from_to)`
---
Note that e.g. `a_string.push_str(b_string.as_slice())` has been left untouched in this PR, since we first need to settle down whether we want to favor the `&*b_string` or the `b_string[]` notation.
This is rebased on top of #19167
cc @alexcrichton @aturon
There is already a test for `union` in the test namespace, but this commit adds a doctest that will appear in the rustdocs.
Someone on IRC said, *Write doctests!*, so here I am.
I am not sure this is the best way to demonstrate the behavior of the union function, so I am open to suggestions for improving this. If I am on the right track I'd be glad to include similar doctests for `intersection`, `difference`, etc.
In regards to:
https://github.com/rust-lang/rust/issues/19253#issuecomment-64836729
This commit:
* Changes the #deriving code so that it generates code that utilizes fewer
reexports (in particur Option::* and Result::*), which is necessary to
remove those reexports in the future
* Changes other areas of the codebase so that fewer reexports are utilized
Add a rustdoc test for union to exhibit how it is used.
There is already a test for union in the test namespace, but this commit
adds a doctest that will appear in the rustdocs.
Add a doctest for the difference function.
Add a doctest for the symmetric_difference function.
Add a doctest for the intersection function.
Update the union et al. doctests based on @Gankro's comments.
Make the union et al. doctests a bit more readable.
Somehow llvm is able to optimize this version of Vec::reserve
into dramatically faster than the old version. In micro-benchmarks
this was 2-10 times faster. It also shaved 14 minutes off of
rust's compile times.
Closes#19281.
Part of #18424
Adds `capacity()` function to VecMap, as per the collections reform.
(Salvaged from #19516, #19523, while we await an RFC regarding `reserve`/`reserve_index` for `VecMap`)
pop calls siftdown, siftdown calls siftdown_range, and siftdown_range
loops on an index that can start as low as 0 and approximately doubles
each iteration.
TrieSet doesn't yet have union, intersection, difference, and symmetric difference functions implemented. Luckily, TrieSet is largely similar to TreeSet, so I was able to reference the implementations of these functions in the latter, and adapt them as necessary to make them work for TrieSet.
One thing that I thought was interesting is that the Iterator yielded by `iter()` for TrieSet iterates over the set's values directly rather than references to the values (whereas I think in most cases I see the Iterator given by `iter()` iterating over immutable references), so for consistency within TrieSet's interface, all of these Iterators also iterate over the values directly. Let me know if all of these should be instead iterating over references.
At the same time remove the `pub use` of the variants in favor of accessing
through the enum type itself. This is a breaking change as the `Found` and
`NotFound` variants must now be imported through `BinarySearchResult` instead of
just `std::slice`.
[breaking-change]
Closes#19271
This is an initial pass at stabilizing the `iter` module. The module is
fairly large, but is also pretty polished, so most of the stabilization
leaves things as they are.
Some changes:
* Due to the new object safety rules, various traits needs to be split
into object-safe traits and extension traits. This includes `Iterator`
itself. While splitting up the traits adds some complexity, it will
also increase flexbility: once we have automatic impls of `Trait` for
trait objects over `Trait`, then things like the iterator adapters
will all work with trait objects.
* Iterator adapters that use up the entire iterator now take it by
value, which makes the semantics more clear and helps catch bugs. Due
to the splitting of Iterator, this does not affect trait objects. If
the underlying iterator is still desired for some reason, `by_ref` can
be used. (Note: this change had no fallout in the Rust distro except
for the useless mut lint.)
* In general, extension traits new and old are following an [in-progress
convention](rust-lang/rfcs#445). As such, they
are marked `unstable`.
* As usual, anything involving closures is `unstable` pending unboxed
closures.
* A few of the more esoteric/underdeveloped iterator forms (like
`RandomAccessIterator` and `MutableDoubleEndedIterator`, along with
various unfolds) are left experimental for now.
* The `order` submodule is left `experimental` because it will hopefully
be replaced by generalized comparison traits.
* "Leaf" iterators (like `Repeat` and `Counter`) are uniformly
constructed by free fns at the module level. That's because the types
are not otherwise of any significance (if we had `impl Trait`, you
wouldn't want to define a type at all).
Closes#17701
Due to renamings and splitting of traits, this is a:
[breaking-change]
This change applies the conventions to unwrap listed in [RFC 430][rfc] to rename
non-failing `unwrap` methods to `into_inner`. This is a breaking change, but all
`unwrap` methods are retained as `#[deprecated]` for the near future. To update
code rename `unwrap` method calls to `into_inner`.
[rfc]: https://github.com/rust-lang/rfcs/pull/430
[breaking-change]
cc #19091
At the same time remove the `pub use` of the variants in favor of accessing
through the enum type itself. This is a breaking change as the `Found` and
`NotFound` variants must now be imported through `BinarySearchResult` instead of
just `std::slice`.
[breaking-change]
Closes#19272
Whilst browsing the source for BinaryHeap, I saw a FIXME for implementing into_iter. I think, since the BinaryHeap is represented internally using just a Vec, just calling into_iter() on the BinaryHeap's data should be sufficient to do what we want here. If this actually isn't the right approach (e.g., I should write a struct MoveItems and appropriate implementation for BinaryHeap instead), let me know and I'll happily rework this.
Both of the tests that I have added pass. This is my first contribution to Rust, so please let me know any ways I can improve this PR!
A single impl supports all of `[T]`, `Vec<T>` and `CVec<T>`.
Once `Iterable` is implemented, we will prefer it to `SlicePrelude`.
But the `with_capacity()` part might become tricky.
This change applies the conventions to unwrap listed in [RFC 430][rfc] to rename
non-failing `unwrap` methods to `into_inner`. This is a breaking change, but all
`unwrap` methods are retained as `#[deprecated]` for the near future. To update
code rename `unwrap` method calls to `into_inner`.
[rfc]: https://github.com/rust-lang/rfcs/pull/430
[breaking-change]
Closes#13159
cc #19091
The impl for [T] also works as impl for slices in general.
By generalizing the impl of StrVector for Vec<Str> to that for
AsSlice<Str>, it becomes much more generic.
Once Iterable is implemented, we will prefer it to AsSlice.
But the with_capacity() part might become tricky.
Signed-off-by: NODA, Kai <nodakai@gmail.com>
This commit makes `Cow` more usable by allowing it to be applied to
unsized types (as was intended) and providing some basic `ToOwned`
implementations on slice types. It also corrects the documentation for
`Cow` to no longer mention `DerefMut`, and adds an example.
Closes#19123
This commit is an implementation of [RFC 240][rfc] when applied to the standard
library. It primarily deprecates the entirety of `string::raw`, `vec::raw`,
`slice::raw`, and `str::raw` in favor of associated functions, methods, and
other free functions. The detailed renaming is:
* slice::raw::buf_as_slice => slice::from_raw_buf
* slice::raw::mut_buf_as_slice => slice::from_raw_mut_buf
* slice::shift_ptr => deprecated with no replacement
* slice::pop_ptr => deprecated with no replacement
* str::raw::from_utf8 => str::from_utf8_unchecked
* str::raw::c_str_to_static_slice => str::from_c_str
* str::raw::slice_bytes => deprecated for slice_unchecked (slight semantic diff)
* str::raw::slice_unchecked => str.slice_unchecked
* string::raw::from_parts => String::from_raw_parts
* string::raw::from_buf_len => String::from_raw_buf_len
* string::raw::from_buf => String::from_raw_buf
* string::raw::from_utf8 => String::from_utf8_unchecked
* vec::raw::from_buf => Vec::from_raw_buf
All previous functions exist in their `#[deprecated]` form, and the deprecation
messages indicate how to migrate to the newer variants.
[rfc]: https://github.com/rust-lang/rfcs/blob/master/text/0240-unsafe-api-location.md
[breaking-change]
Closes#17863
This commit is an implementation of [RFC 240][rfc] when applied to the standard
library. It primarily deprecates the entirety of `string::raw`, `vec::raw`,
`slice::raw`, and `str::raw` in favor of associated functions, methods, and
other free functions. The detailed renaming is:
* slice::raw::buf_as_slice => slice::with_raw_buf
* slice::raw::mut_buf_as_slice => slice::with_raw_mut_buf
* slice::shift_ptr => deprecated with no replacement
* slice::pop_ptr => deprecated with no replacement
* str::raw::from_utf8 => str::from_utf8_unchecked
* str::raw::c_str_to_static_slice => str::from_c_str
* str::raw::slice_bytes => deprecated for slice_unchecked (slight semantic diff)
* str::raw::slice_unchecked => str.slice_unchecked
* string::raw::from_parts => String::from_raw_parts
* string::raw::from_buf_len => String::from_raw_buf_len
* string::raw::from_buf => String::from_raw_buf
* string::raw::from_utf8 => String::from_utf8_unchecked
* vec::raw::from_buf => Vec::from_raw_buf
All previous functions exist in their `#[deprecated]` form, and the deprecation
messages indicate how to migrate to the newer variants.
[rfc]: https://github.com/rust-lang/rfcs/blob/master/text/0240-unsafe-api-location.md
[breaking-change]
Closes#17863
'Numeric' is the proper name of the unicode character class,
and this frees up the word 'digit' for ascii use in libcore.
Since I'm going to rename `Char::is_digit_radix` to
`is_digit`, I am not leaving a deprecated method in place,
because that would just cause name clashes, as both
`Char` and `UnicodeChar` are in the prelude.
[breaking-change]
This PR completes the removal of the runtime system and green-threaded abstractions as part of implementing [RFC 230](https://github.com/rust-lang/rfcs/pull/230).
Specifically:
* It removes the `Runtime` trait, welding the scheduling infrastructure directly to native threads.
* It removes `libgreen` and `libnative` entirely.
* It rewrites `sync::mutex` as a trivial layer on top of native mutexes. Eventually, the two modules will be merged.
* It hides the vast majority of `std::rt`.
This completes the basic task of removing the runtime system (I/O and scheduling) and components that depend on it.
After this lands, a follow-up PR will pull the `rustrt` crate back into `std`, turn `std::task` into `std::thread` (with API changes to go along with it), and completely cut out the remaining startup/teardown sequence. Other changes, including new [TLS](https://github.com/rust-lang/rfcs/pull/461) and synchronization are in the RFC or pre-RFC phase.
Closes#17325Closes#18687
[breaking-change]
r? @alexcrichton
Previously, the entire runtime API surface was publicly exposed, but
that is neither necessary nor desirable. This commit hides most of the
module, using librustrt directly as needed. The arrangement will need to
be revisited when rustrt is pulled into std.
[breaking-change]
Closes#18415
This links [`std::str`](http://doc.rust-lang.org/std/str/index.html) documentation to [literals](http://doc.rust-lang.org/reference.html#literals) in the reference guide and collects examples of literals into one group at the beginning of the section. ~~The new tables are not exhaustive (some escapes were skipped) and so I try to link back to the respective sections where more detail is located.~~ The tables are are mostly exhaustive. I misunderstood some of the whitespace codes.
I don't think the tables actually look that nice if that's important and I'm not sure how it could be improved. I think it does do a good job of collecting available options together. I think listing the escapes together is particularly helpful because they vary with type and are embedded in paragraphs.
[EDIT]
The [ascii table](http://man-ascii.com/) is here and may be useful.
This commit makes `Cow` more usable by allowing it to be applied to
unsized types (as was intended) and providing some basic `ToOwned`
implementations on slice types. It also corrects the documentation for
`Cow` to no longer mention `DerefMut`, and adds an example.
This commit changes `AsSlice` to work on unsized types, and changes the
`impl` for `&[T]` to `[T]`. Aside from making the trait more general,
this also helps some ongoing work with method resolution changes.
This is a breaking change: code that uses generics bounded by `AsSlice`
will have to change. In particular, such code previously often took
arguments of type `V` where `V: AsSlice<T>` by value. These should now
be taken by reference:
```rust
fn foo<Sized? V: AsSlice<T>>(v: &V) { .. }
```
A few std lib functions have been changed accordingly.
[breaking-change]
`slice_shift_char` splits a `str` into it's leading `char` and the remainder of the `str`. Currently, it returns a `(Option<char>, &str)` such that:
"bar".slice_shift_char() => (Some('b'), "ar")
"ar".slice_shift_char() => (Some('a'), "r")
"r".slice_shift_char() => (Some('r'), "")
"".slice_shift_char() => (None, "")
This is a little odd. Either a `str` can be split into both a head and a tail or it cannot. So the return type should be `Option<(char, &str)>`. With the current behaviour, in the case of the empty string, the `str` returned is meaningless - it is always the empty string.
This PR changes `slice_shift_char` so that:
"bar".slice_shift_char() => Some(('b', "ar"))
"ar".slice_shift_char() => Some(('a', "r"))
"r".slice_shift_char() => Some(('r', ""))
"".slice_shift_char() => None
Following [the collections reform
RFC](https://github.com/rust-lang/rfcs/pull/235),
this commit adds a new `borrow` module to libcore.
The module contains traits for borrowing data (`BorrowFrom` and
`BorrowFromMut`),
generalized cloning (`ToOwned`), and a clone-on-write smartpointer (`Cow`).
This breaks code that referred to variant names in the same namespace as
their enum. Reexport the variants in the old location or alter code to
refer to the new locations:
```
pub enum Foo {
A,
B
}
fn main() {
let a = A;
}
```
=>
```
pub use self::Foo::{A, B};
pub enum Foo {
A,
B
}
fn main() {
let a = A;
}
```
or
```
pub enum Foo {
A,
B
}
fn main() {
let a = Foo::A;
}
```
[breaking-change]
`slice_shift_char` splits a `str` into it's leading `char` and the remainder
of the `str`. Currently, it returns a `(Option<char>, &str)` such that:
"bar".slice_shift_char() => (Some('b'), "ar")
"ar".slice_shift_char() => (Some('a'), "r")
"r".slice_shift_char() => (Some('r'), "")
"".slice_shift_char() => (None, "")
This is a little odd. Either a `str` can be split into both a head and a
tail or it cannot. So the return type should be `Option<(char, &str)>`.
With the current behaviour, in the case of the empty string, the `str`
returned is meaningless - it is always the empty string.
This commit changes slice_shift_char so that:
"bar".slice_shift_char() => Some(('b', "ar"))
"ar".slice_shift_char() => Some(('a', "r"))
"r".slice_shift_char() => Some(('r', ""))
"".slice_shift_char() => None
[breaking-change]
Fix for task in Metabug #18009 (Rebased version of https://github.com/rust-lang/rust/pull/18170)
This changes much of about how RingBuf functions. `lo`, `nelts` are replaced by a more traditional `head` and`tail`. The `Vec<Option<T>>` is replaced by a bare pointer that is managed by the `RingBuf` itself. This also expects the ring buffer to always be size that is a power of 2.
This change also includes a number of new tests to cover the some areas that could be of concern with manual memory management.
The benchmarks have been reworked since the old ones were benchmarking of the Ring buffers growth rather then the actual test.
The unit test suite have been expanded, and exposed some bugs in `fn get()` and `fn get_mut()`
## Benchmark
**Before:**
```
test ring_buf::tests::bench_grow_1025 ... bench: 8919 ns/iter (+/- 87)
test ring_buf::tests::bench_iter_1000 ... bench: 924 ns/iter (+/- 28)
test ring_buf::tests::bench_mut_iter_1000 ... bench: 918 ns/iter (+/- 6)
test ring_buf::tests::bench_new ... bench: 15 ns/iter (+/- 0)
test ring_buf::tests::bench_pop_100 ... bench: 294 ns/iter (+/- 9)
test ring_buf::tests::bench_pop_front_100 ... bench: 948 ns/iter (+/- 32)
test ring_buf::tests::bench_push_back_100 ... bench: 291 ns/iter (+/- 16)
test ring_buf::tests::bench_push_front_100 ... bench: 311 ns/iter (+/- 27
```
**After:**
```
test ring_buf::tests::bench_grow_1025 ... bench: 2209 ns/iter (+/- 169)
test ring_buf::tests::bench_iter_1000 ... bench: 534 ns/iter (+/- 27)
test ring_buf::tests::bench_mut_iter_1000 ... bench: 515 ns/iter (+/- 28)
test ring_buf::tests::bench_new ... bench: 11 ns/iter (+/- 0)
test ring_buf::tests::bench_pop_100 ... bench: 170 ns/iter (+/- 5)
test ring_buf::tests::bench_pop_front_100 ... bench: 171 ns/iter (+/- 11)
test ring_buf::tests::bench_push_back_100 ... bench: 172 ns/iter (+/- 13)
test ring_buf::tests::bench_push_front_100 ... bench: 158 ns/iter (+/- 12)
```
A recent change turned off inheritance for the #[stable] by default, but
failed to catch all the cases where this was being used in std. This
patch fixes that problem.
I found some occurrences of "failure" and "fails" in the documentation. I changed them to "panics" if it means a task panic. Otherwise I left it as is, or changed it to "errors" to clearly distinguish them.
Also, I made a minor fix that is breaking the layout of a module page. "Example" is shown in an irrelevant place from the following page: http://doc.rust-lang.org/std/os/index.html
-Adds unit tests for fn get() and fn get_mut() which are currently untested
-Adds unit tests to verify growth of the ringbuffer when reserve is called.
-Adds unit tests to confirm that dropping of items is correct
Move ringbuf to use a raw buffer instead of Option<T>
This implements a considerable portion of rust-lang/rfcs#369 (tracked in #18640). Some interpretations had to be made in order to get this to work. The breaking changes are listed below:
[breaking-change]
- `core::num::{Num, Unsigned, Primitive}` have been deprecated and their re-exports removed from the `{std, core}::prelude`.
- `core::num::{Zero, One, Bounded}` have been deprecated. Use the static methods on `core::num::{Float, Int}` instead. There is no equivalent to `Zero::is_zero`. Use `(==)` with `{Float, Int}::zero` instead.
- `Signed::abs_sub` has been moved to `std::num::FloatMath`, and is no longer implemented for signed integers.
- `core::num::Signed` has been removed, and its methods have been moved to `core::num::Float` and a new trait, `core::num::SignedInt`. The methods now take the `self` parameter by value.
- `core::num::{Saturating, CheckedAdd, CheckedSub, CheckedMul, CheckedDiv}` have been removed, and their methods moved to `core::num::Int`. Their parameters are now taken by value. This means that
- `std::time::Duration` no longer implements `core::num::{Zero, CheckedAdd, CheckedSub}` instead defining the required methods non-polymorphically.
- `core::num::{zero, one, abs, signum}` have been deprecated. Use their respective methods instead.
- The `core::num::{next_power_of_two, is_power_of_two, checked_next_power_of_two}` functions have been deprecated in favor of methods defined a new trait, `core::num::UnsignedInt`
- `core::iter::{AdditiveIterator, MultiplicativeIterator}` are now only implemented for the built-in numeric types.
- `core::iter::{range, range_inclusive, range_step, range_step_inclusive}` now require `core::num::Int` to be implemented for the type they a re parametrized over.
Throughout the docs, "failure" was replaced with "panics" if it means a
task panic. Otherwise, it remained as is, or changed to "errors" to
clearly differentiate it from a task panic.
Ensured that Extend & FromIterator are implemented for the libcollection.
Removed the fact that FromIterator had to be implemented in order to implement Extend, as it did not make sense for LruCache (it needs to be given a size and there are no Default for LruCache).
Changed the name from Extend to Extendable.
Part of #18424
