Since we don’t have Deprecated stability level anymore, the only other source of information is
deprecated-since version, which conveniently to us, only exists if the symbol is deprecated.
Fixes#21789
`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
`cp -a` is a GNU extension. Use an alternate combinaison of POSIX options
(`-PRp`) that do nearly the same.
The difference is `-a` will preserve context, links and xattr attributes,
whereas `-p` not. But as we use it only for copy a file, there is no
difference in the current context.
The Rust Programming Language book has no explanation of what `i32` actually means. I have added an explanation for the first time the reader encounters this type.
@steveklabnik Trying out the Glossary idea.
Added the paragraph about 'complicated words' because I think it would be useful to those contributing to the book. Maybe this should not be here
This snuck through my refactor.
Would it be worth the effort to have a test pass that attempts to lint the code for all targets, even if it's not feasible to actually build and test it?
The book in "hello-world" tells that there are configs for some programs and gives a link to main repo's src/etc. Actually, these configs moved to separate repos some days ago. This PR adds a markdown file with links and moves "hello-world" link about editors to point directly to this new file.
`pipe(2)`, under FreeBSD and OpenBSD return a bidirectionnal pipe. So
reading from the writer would block (waiting data) instead of returning
an error.
like for FreeBSD, disable the test for OpenBSD.
This is a patch for #22291.
PLEASE_BENCH=1 adds --bench to the arguments passed to the executable to be tested. At the moment, compiletest does not accept a --bench argument, because it is not needed for any test in src/test/, even the tests in src/test/bench do not use #[bench].
I have updated the makefile to only add the --bench flag for crate tests. I do not think that changing compiletest add --bench to the run arguments of all compile tests makes sense, because it would mess up tests which check command line arguments. Also the bench option can be added as comment in a compile test as well.
It is not totally clear if we should just use whitespace, or if the full
unicode word-breaking algorithm is more correct. If there is demand we
can reconsider this decision (and consider the precise algorithm to use
in detail).
cc #15628.
This includes everything necessary for promoting borrows of constant rvalues to `'static`.
That is, `&expr` will have the type `&'static T` if `const T: &'static T = &expr;` is valid.
There is a small exception, dereferences of raw pointers, as they misbehave.
They still "work" in constants as I didn't want to break legitimate uses (are there any?).
The qualification done here can be expanded to allow simple CTFE via `const fn`.
Nonetheless, as this commit demonstrates, the previous commits was a [breaking-change].
In practice, breakage is focused on functions of this form:
```rust
fn foo(..., object: Box<FnMut()>)
````
where `FnMut()` could be any trait object type. The older scheme defaulted objects in argument
position so that they were bounded by a fresh lifetime:
```rust
fn foo<'a>(..., object: Box<FnMut()+'a>)
```
This meant that the object could contain borrowed data. The newer
scheme defaults to a lifetime bound of `'static`:
```rust
fn foo(..., object: Box<FnMut()+'static>)
```
This means that the object cannot contain borrowed data. In some cases, the best fix
is to stop using `Box`:
```rust
fn foo(..., object: &mut FnMut())
```
but another option is to write an explicit annotation for the `'a`
lifetime that used to be implicit. Both fixes are demonstrated in
this commit.
