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::\*, Result::\*, and Ordering::\*), which is necessary to
remove those reexports in the future
* Changes other areas of the codebase so that fewer reexports are utilized
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
Right now, `DerefMut` is not `for Sized?`, so you can't impl `DerefMut<T> for Foo` where `Foo` is unsized. However, there is no reason that it can't be `for Sized?`, so this pull request fixes the issue.
Closes#19493.
Added the example from [this Reddit thread][1], reworked to be more robust with correct logic (first link skipped the 0th and 1st Fibonacci numbers, second forgot about the last two valid values before overflow). Will yield all Fibonacci numbers sequentially in the range `[0, <u32 as Int>::max_value())`.
If the example is too complicated I can change it to a more naive version, perhaps using signed integers to check for overflow instead of `Option` and `.checked_add()`.
Also reworded the doc comments to clarify the usage and behavior of `Unfold`, as the thread suggested that it wasn't really clear how `Unfold` worked and when one should use it.
This change is in the `core` crate but I based the example on `std` since that's where most readers will find the example. I included a note about `core` for clarity. Edit: removed.
Tested with `rustdoc src/libcore/lib.rs`. Rebased against latest master as of the creation of this PR.
[1]: http://www.reddit.com/r/rust/comments/2ny8r1/a_question_about_loops/cmighu4?context=10000
1. Made small improvements to the docs for checked_sub, checked_mul and checked_div.
2. Updated a confusingly outdated comment for intrinsics, noticed before at <https://stackoverflow.com/questions/23582931/>.
This continues the work @thestinger started in #18885 (which hasn't landed yet, so wait for that to land before landing this one). Instead of adding more methods to `BufReader`, this just allows a `&[u8]` to be used directly as a `Reader`. It also adds an impl of `Writer` for `&mut [u8]`.
Comparison traits have gained an `Rhs` input parameter that defaults to `Self`. And now the comparison operators can be overloaded to work between different types. In particular, this PR allows the following operations (and their commutative versions):
- `&str` == `String` == `CowString`
- `&[A]` == `&mut [B]` == `Vec<C>` == `CowVec<D>` == `[E, ..N]` (for `N` up to 32)
- `&mut A` == `&B` (for `Sized` `A` and `B`)
Where `A`, `B`, `C`, `D`, `E` may be different types that implement `PartialEq`. For example, these comparisons are now valid: `string == "foo"`, and `vec_of_strings == ["Hello", "world"]`.
[breaking-change]s
Since the `==` may now work on different types, operations that relied on the old "same type restriction" to drive type inference, will need to be type annotated. These are the most common fallout cases:
- `some_vec == some_iter.collect()`: `collect` needs to be type annotated: `collect::<Vec<_>>()`
- `slice == &[a, b, c]`: RHS doesn't get coerced to an slice, use an array instead `[a, b, c]`
- `lhs == []`: Change expression to `lhs.is_empty()`
- `lhs == some_generic_function()`: Type annotate the RHS as necessary
cc #19148
r? @aturon
Implements RFC 438.
Fixes#19092.
This is a [breaking-change]: change types like `&Foo+Send` or `&'a mut Foo+'a` to `&(Foo+Send)` and `&'a mut (Foo+'a)`, respectively.
r? @brson
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 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](https://github.com/rust-lang/rfcs/pull/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
A slice iterator is isomorphic to a slice, just with a slightly
different form: storing start and end pointers rather than start pointer
and length. This patch reflects this by making converting between them
as easy as `iter.as_slice()` (or even `iter[]` if the shorter lifetime
is ok). That is, `slice.iter().as_slice() == slice`.
r? @aturon
A slice iterator is isomorphic to a slice, just with a slightly
different form: storing start and end pointers rather than start pointer
and length. This patch reflects this by making converting between them
as easy as `iter.as_slice()` (or even `iter[]` if the shorter lifetime
is ok). That is, `slice.iter().as_slice() == slice`.
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
Just like we do with AsSlice
This comes in handy when dealing with iterator-centric APIs (`IntoIterator`!) and you want to receive an `Iterator<S> where S: Str` argument. Without this PR, e.g. you can't receive `&["a", "b"].iter()` instead you'll have to type `&["a", "b"].iter().map(|&x| x)` (A similar thing happens with `&[String]`).
r? @aturon
Full disclaimer: I haven't run `make`/`make check` yet (All my cores are busy)
