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.
* The lint visitor's visit_ty method did not recurse, and had a
reference to the now closed#10894
* The newly enabled recursion has only affected the `deprectated` lint
which now detects uses of deprecated items in trait impls and
function return types
* Renamed some references to `CowString` and `CowVec` to `Cow<str>` and
`Cow<[T]>`, respectively, which appear outside of the crate which
defines them
* Replaced a few instances of `InvariantType<T>` with
`PhantomData<Cell<T>>`
* Disabled the `deprecated` lint in several places that
reference/implement traits on deprecated items which will get cleaned
up in the future
* Disabled the `exceeding_bitshifts` lint for
compile-fail/huge-array-simple test so it doesn't shadow the expected
error on 32bit systems
* Unfortunately, this means that if a library declares
`#![deny(deprecated)]` and marks anything as deprecated, it will have
to disable the lint for any uses of said item, e.g. any impl the now
deprecated item
For any library that denies deprecated items but has deprecated items
of its own, this is a [breaking-change]
Specifically, the following actions were takend:
* The `copy_memory` and `copy_nonoverlapping_memory` functions
to drop the `_memory` suffix (as it's implied by the functionality). Both
functions are now marked as `#[stable]`.
* The `set_memory` function was renamed to `write_bytes` and is now stable.
* The `zero_memory` function is now deprecated in favor of `write_bytes`
directly.
* The `Unique` pointer type is now behind its own feature gate called `unique`
to facilitate future stabilization.
[breaking-change]
Specifically, the following actions were taken:
* The `copy_memory` and `copy_nonoverlapping_memory` functions
to drop the `_memory` suffix (as it's implied by the functionality). Both
functions are now marked as `#[stable]`.
* The `set_memory` function was renamed to `write_bytes` and is now stable.
* The `zero_memory` function is now deprecated in favor of `write_bytes`
directly.
* The `Unique` pointer type is now behind its own feature gate called `unique`
to facilitate future stabilization.
* All type parameters now are `T: ?Sized` wherever possible and new clauses were
added to the `offset` functions to require that the type is sized.
[breaking-change]
... 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.
This commit stabilizes `std::borrow`, making the following modifications
to catch up the API with language changes:
* It renames `BorrowFrom` to `Borrow`, as was originally intended (but
blocked for technical reasons), and reorders the parameters
accordingly.
* It moves the type parameter of `ToOwned` to an associated type. This
is somewhat less flexible, in that each borrowed type must have a
unique owned type, but leads to a significant simplification for
`Cow`. Flexibility can be regained by using newtyped slices, which is
advisable for other reasons anyway.
* It removes the owned type parameter from `Cow`, making the type much
less verbose.
* Deprecates the `is_owned` and `is_borrowed` predicates in favor of
direct matching.
The above API changes are relatively minor; the basic functionality
remains the same, and essentially the whole module is now marked
`#[stable]`.
[breaking-change]
This commit is an implementation of [RFC 823][rfc] which is another pass over
the `std::hash` module for stabilization. The contents of the module were not
entirely marked stable, but some portions which remained quite similar to the
previous incarnation are now marked `#[stable]`. Specifically:
[rfc]: https://github.com/rust-lang/rfcs/blob/master/text/0823-hash-simplification.md
* `std::hash` is now stable (the name)
* `Hash` is now stable
* `Hash::hash` is now stable
* `Hasher` is now stable
* `SipHasher` is now stable
* `SipHasher::new` and `new_with_keys` are now stable
* `Hasher for SipHasher` is now stable
* Many `Hash` implementations are now stable
All other portions of the `hash` module remain `#[unstable]` as they are less
commonly used and were recently redesigned.
This commit is a breaking change due to the modifications to the `std::hash` API
and more details can be found on the [RFC][rfc].
Closes#22467
[breaking-change]
This breaks all implementors of FromIterator, as they must now accept IntoIterator instead of Iterator. The fix for this is generally trivial (change the bound, and maybe call into_iter() on the argument to get the old argument).
Users of FromIterator should be unaffected because Iterators are IntoIterator.
[breaking-change]
This breaks all implementors of Extend, as they must now accept IntoIterator instead of Iterator. The fix for this is generally trivial (change the bound, and maybe call into_iter() on the argument to get the old argument).
Users of Extend should be unaffected because Iterators are IntoIterator.
[breaking-change]
This commit is an implementation of [RFC 823][rfc] which is another pass over
the `std::hash` module for stabilization. The contents of the module were not
entirely marked stable, but some portions which remained quite similar to the
previous incarnation are now marked `#[stable]`. Specifically:
[rfc]: https://github.com/rust-lang/rfcs/blob/master/text/0823-hash-simplification.md
* `std::hash` is now stable (the name)
* `Hash` is now stable
* `Hash::hash` is now stable
* `Hasher` is now stable
* `SipHasher` is now stable
* `SipHasher::new` and `new_with_keys` are now stable
* `Hasher for SipHasher` is now stable
* Many `Hash` implementations are now stable
All other portions of the `hash` module remain `#[unstable]` as they are less
commonly used and were recently redesigned.
This commit is a breaking change due to the modifications to the `std::hash` API
and more details can be found on the [RFC][rfc].
Closes#22467
[breaking-change]
The data pointer used in the slice is never null, using assume() to tell
LLVM about it gets rid of various unneeded null checks when iterating
over the slice.
Since the snapshot compiler is still using an older LLVM version, omit
the call in stage0, because compile times explode otherwise.
Benchmarks from #18193
````
running 5 tests
test _range ... bench: 33329 ns/iter (+/- 417)
test assembly ... bench: 33299 ns/iter (+/- 58)
test enumerate ... bench: 33318 ns/iter (+/- 83)
test iter ... bench: 33311 ns/iter (+/- 130)
test position ... bench: 33300 ns/iter (+/- 47)
test result: ok. 0 passed; 0 failed; 0 ignored; 5 measured
````
Fixes#18193
Now that the necessary associated types exist for the `IntoIterator` trait this
commit stabilizes the trait as-is as well as all existing implementations.
`IntoIterator` now has an extra associated item:
``` rust
trait IntoIterator {
type Item;
type IntoIter: Iterator<Self=Self::Item>;
}
```
This lets you bind the iterator \"`Item`\" directly when writing generic functions:
``` rust
// hypothetical change, not included in this PR
impl Extend<T> for Vec<T> {
// you can now write
fn extend<I>(&mut self, it: I) where I: IntoIterator<Item=T> { .. }
// instead of
fn extend<I: IntoIterator>(&mut self, it: I) where I::IntoIter: Iterator<Item=T> { .. }
}
```
The downside is that now you have to write an extra associated type in your `IntoIterator` implementations:
``` diff
impl<T> IntoIterator for Vec<T> {
+ type Item = T;
type IntoIter = IntoIter<T>;
fn into_iter(self) -> IntoIter<T> { .. }
}
```
Because this breaks all downstream implementations of `IntoIterator`, this is a [breaking-change]
---
r? @aturon
This PR is an optimization of the `FromIterator` implementation of `Vec`
Benchmark: https://gist.github.com/alexcrichton/03d666159a28a80e7c70
Before:
test macro_repeat1 ... bench: 57 ns/iter (+/- 1)
test macro_repeat2 ... bench: 56 ns/iter (+/- 1)
test map_clone1 ... bench: 828 ns/iter (+/- 13)
test map_clone2 ... bench: 828 ns/iter (+/- 8)
test repeat1 ... bench: 1104 ns/iter (+/- 10)
test repeat2 ... bench: 1106 ns/iter (+/- 11)
After:
test macro_repeat1 ... bench: 75 ns/iter (+/- 21)
test macro_repeat2 ... bench: 59 ns/iter (+/- 31)
test map_clone1 ... bench: 34 ns/iter (+/- 22)
test map_clone2 ... bench: 52 ns/iter (+/- 21)
test repeat1 ... bench: 34 ns/iter (+/- 11)
test repeat2 ... bench: 33 ns/iter (+/- 12)
The idea behind this optimization is to avoid all bounds checks for space
already allocated into the vector. This may involve running the iterator twice,
but the first run of the iterator should be optimizable to a memcpy or memset if
possible.
The same treatment can in theory be applied to `Vec::extend` but the benchmarks
for that currently get *worse* if the change is applied. This appears to be some
LLVM optimizations going awry but it's seems prudent to land at least the
`collect` portion beforehand.
This PR is an optimization of the `FromIterator` implementation of `Vec`
Benchmark: https://gist.github.com/alexcrichton/03d666159a28a80e7c70
Before:
test macro_repeat1 ... bench: 57 ns/iter (+/- 1)
test macro_repeat2 ... bench: 56 ns/iter (+/- 1)
test map_clone1 ... bench: 828 ns/iter (+/- 13)
test map_clone2 ... bench: 828 ns/iter (+/- 8)
test repeat1 ... bench: 1104 ns/iter (+/- 10)
test repeat2 ... bench: 1106 ns/iter (+/- 11)
After:
test macro_repeat1 ... bench: 75 ns/iter (+/- 21)
test macro_repeat2 ... bench: 59 ns/iter (+/- 31)
test map_clone1 ... bench: 34 ns/iter (+/- 22)
test map_clone2 ... bench: 52 ns/iter (+/- 21)
test repeat1 ... bench: 34 ns/iter (+/- 11)
test repeat2 ... bench: 33 ns/iter (+/- 12)
The idea behind this optimization is to avoid all bounds checks for space
already allocated into the vector. This may involve running the iterator twice,
but the first run of the iterator should be optimizable to a memcpy or memset if
possible.
The same treatment can in theory be applied to `Vec::extend` but the benchmarks
for that currently get *worse* if the change is applied. This appears to be some
LLVM optimizations going awry but it's seems prudent to land at least the
`collect` portion beforehand.
Port `core::ptr::Unique` to have `PhantomData`. Add `PhantomData` to
`TypedArena` and `Vec` as well.
As a drive-by, switch `ptr::Unique` from a tuple-struct to a struct
with fields.
This is in preparation for stabilization of the `IntoIterator` trait. All
implementations and references to `Iter` need to be renamed to `IntoIter`.
[breaking-change]
