The exact semantics of `is_null` on unsized pointers are still debatable,
especially for trait objects. It may be legal to call `*mut self`
methods on a trait object someday, as with Go interfaces, so `is_null`
might need to validate the vtable pointer too.
For `as_ref` and `as_mut`, we're assuming that you cannot have a non-null
data pointer with a null vtable, so casting the unsized check is fine.
`NonZero::is_zero()` was already casting all pointers to thin `*mut u8`
to check for null. It seems reasonable to apply that for `is_null()` in
general, and then unsized fat pointers can also be used with `as_ref()`
and `as_mut()` to get fat references.
Add ..= to the parser
Add ..= to libproc_macro
Add ..= to ICH
Highlight ..= in rustdoc
Update impl Debug for RangeInclusive to ..=
Replace `...` to `..=` in range docs
Make the dotdoteq warning point to the ...
Add warning for ... in expressions
Updated more tests to the ..= syntax
Updated even more tests to the ..= syntax
Updated the inclusive_range entry in unstable book
Customize `<FlatMap as Iterator>::fold`
`FlatMap` can use internal iteration for its `fold`, which shows a
performance advantage in the new benchmarks:
test iter::bench_flat_map_chain_ref_sum ... bench: 4,354,111 ns/iter (+/- 108,871)
test iter::bench_flat_map_chain_sum ... bench: 468,167 ns/iter (+/- 2,274)
test iter::bench_flat_map_ref_sum ... bench: 449,616 ns/iter (+/- 6,257)
test iter::bench_flat_map_sum ... bench: 348,010 ns/iter (+/- 1,227)
... where the "ref" benches are using `by_ref()` that isn't optimized.
So this change shows a decent advantage on its own, but much more when
combined with a `chain` iterator that also optimizes `fold`.
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
Make the "main" constructors of NonZero/Shared/Unique return Option
Per discussion in https://github.com/rust-lang/rust/issues/27730#issuecomment-303939441.
This is a breaking change to unstable APIs.
The old behavior is still available under the name `new_unchecked`. Note that only that one can be `const fn`, since `if` is currently not allowed in constant contexts.
In the case of `NonZero` this requires adding a new `is_zero` method to the `Zeroable` trait. I mildly dislike this, but it’s not much worse than having a `Zeroable` trait in the first place. `Zeroable` and `NonZero` are both unstable, this can be reworked later.
This removes the need for a 128 bit storage by making use of the fact that
there can be either no over/underflow, either one or both, and each time
the target type suffices to hold the limit for comparison.
The downside is that the code looks a bit more complex.
This test code included in this commit is from @oyvindln 's PR. They also
greatly helped fixing a number of errors I made along the way. Thanks a lot!
Delete deprecated & unstable range-specific `step_by`
Using the new one is annoying while this one exists, since the inherent method hides the one on iterator.
Tracking issue: #27741
Replacement: #41439
Deprecation: #42310 for 1.19
Fixes#41477
add `FromStr` Impl for `char`
fixes#24939.
is it possible to use pub(restricted) instead of using a stability attribute for the internal error representation? is it needed at all?
Add a travis builder for wasm32-unknown-emscripten
This commits add an entry to travis matrix that will execute wasm32-unknown-emscripten tests suites.
- Emscripten for asmjs was updated to sdk-1.37.13-64bit
- The tests are run with node 8.0.0 (it can execute wasm)
- A wrapper script is used to run each test from the directory where it is (workaround for https://github.com/kripken/emscripten/issues/4542)
- Some tests are ignore, see #42629 and #42630
Pursuant to issue #25663, this commit adds the max and min functions to the Ord trait, enabling items that implement Ord to use UFCS (ex. 1.max(2)) instead of the longer std::cmp::max(1,2) format.
Add an in-place rotate method for slices to libcore
A helpful primitive for moving chunks of data around inside a slice.
For example, if you have a range selected and are drag-and-dropping it somewhere else (Example from [Sean Parent's talk](https://youtu.be/qH6sSOr-yk8?t=560)).
(If this should be an RFC instead of a PR, please let me know.)
Edit: changed example
Override size_hint and propagate ExactSizeIterator for iter::StepBy
Generally useful, but also a prerequisite for moving a bunch of unit tests off `Range*::step_by`.
A small non-breaking subset of https://github.com/rust-lang/rust/pull/42110 (which I closed).
Includes two small documentation changes @ivandardi requested on that PR.
r? @alexcrichton
A helpful primitive for moving chunks of data around inside a slice.
In particular, adding elements to the end of a Vec then moving them
somewhere else, as a way to do efficient multiple-insert. (There's
drain for efficient block-remove, but no easy way to block-insert.)
Talk with another example: <https://youtu.be/qH6sSOr-yk8?t=560>
Not being an enum improves ergonomics, especially since NonEmpty could be Empty. It can still be iterable without an extra "done" bit by making the range have !(start <= end), which is even possible without changing the Step trait.
Implements RFC 1980
