impl FromIterator<()> for ()
This just collapses all unit items from an iterator into one. This is
more useful when combined with higher-level abstractions, like
collecting to a `Result<(), E>` where you only care about errors:
```rust
use std::io::*;
data = vec![1, 2, 3, 4, 5];
let res: Result<()> = data.iter()
.map(|x| writeln!(stdout(), "{}", x))
.collect();
assert!(res.is_ok());
```
Remove `T: Sized` on pointer `as_ref()` and `as_mut()`
`NonZero::is_zero()` was already casting all pointers to thin `*mut u8` to check for null. The same test on unsized fat pointers can also be used with `as_ref()` and `as_mut()` to get fat references.
(This PR formerly changed `is_null()` too, but checking just the data pointer is not obviously correct for trait objects, especially if `*const self` sorts of methods are ever allowed.)
This affects regular code generation as well as constant evaluation in trans,
but not the HIR constant evaluator because that one returns an error for
overflowing casts and NaN-to-int casts. That error is conservatively
correct and we should be careful to not accept more code in constant
expressions.
The changes to code generation are guarded by a new -Z flag, to be able
to evaluate the performance impact. The trans constant evaluation changes
are unconditional because they have no run time impact and don't affect
type checking either.
- added some old code that used ExplicitSelf::determine to check for eqtype with the expected self type in the simple cases
- this fixes problems with error messages being worse in those cases, which caused some compile-fail tests to fail
- removed the inherent impls compile-fail test, because we’ll be
supporting them
- remove E0308-2 because it’s gonna be supported now (behind a feature
gate)
- replaced the mismatched method receiver error message with something
better, so fixed the tests that that broke
Rewrote ExplicitSelf, adding a new `Other` variant for arbitrary self
types. It’s a bit more sophisticated now, and checks for type equality,
so you have to pass the type context and param env as arguments.
There’s a borrow-checker error here that I have to fix
Rewrote check_method_receiver, so it acts as if arbitrary self types
are allowed, and then checks for ExplicitSelf::Other at the end and
disallows it unless the feature is present.
If the feature is enabled, allow method `self` types to be any type
that auto-derefs to `self`.
- Currently, this supports inherent methods as well as trait methods.
The plan AFAIK is to only allow this for trait methods, so I guess it
won’t stay this way
- Dynamic dispatch isn’t implemented yet, so the compiler will ICE if
you define a trait method that takes `self: Rc<Self>` and try to call
it on an `Rc<Trait>`. I will probably just make those methods
non-object-safe initially.
Pretty print parens around casts on the LHS of `<`/`<<`
When pretty printing a cast expression occuring on the LHS of a `<` or `<<` expression, we should add parens around the cast. Otherwise, the `<`/`<<` gets interpreted as the beginning of the generics for the type on the RHS of the cast.
Consider:
$ cat parens_cast.rs
macro_rules! negative {
($e:expr) => { $e < 0 }
}
fn main() {
negative!(1 as i32);
}
Before this PR, the output of the following is not valid Rust:
$ rustc -Z unstable-options --pretty=expanded parens_cast.rs
#![feature(prelude_import)]
#![no_std]
#[prelude_import]
use std::prelude::v1::*;
#[macro_use]
extern crate std as std;
macro_rules! negative(( $ e : expr ) => { $ e < 0 });
fn main() { 1 as i32 < 0; }
After this PR, the output of the following is valid Rust:
$ rustc -Z unstable-options --pretty=expanded parens_cast.rs
#![feature(prelude_import)]
#![no_std]
#[prelude_import]
use std::prelude::v1::*;
#[macro_use]
extern crate std as std;
macro_rules! negative(( $ e : expr ) => { $ e < 0 });
fn main() { (1 as i32) < 0; }
I've gone through several README/wiki style documents but I'm still not sure where to test this though. I'm not even sure if this sort of thing is tested...
rustdoc: add #[allow(unused)] to every doctest
More information in #45750 - this is behavior that was documented but not actually implemented.
I also reordered how outer attributes are applied to doctests. Previously, attributes from `#![doc(test(attr(...)))]` would be applied *after* attributes from within the test itself, meaning if a doctest tried to override lints that would be set crate-wide, it wouldn't work at all. This gives a better scope of how lints can be applied.
Closes#45750
Handle anon lifetime arg being returned with named lifetime return type
When there's a lifetime mismatch between an argument with an anonymous
lifetime being returned in a method with a return type that has a named
lifetime, show specialized lifetime error pointing at argument with a
hint to give it an explicit lifetime matching the return type.
```
error[E0621]: explicit lifetime required in the type of `other`
--> file2.rs:21:21
|
17 | fn bar(&self, other: Foo) -> Foo<'a> {
| ----- consider changing the type of `other` to `Foo<'a>`
...
21 | other
| ^^^^^ lifetime `'a` required
```
Follow up to #44124 and #42669. Fix#44684.
RwLock guards are Sync if T is
Currently, the compiler requires `T` to also be `Send`. There is no reason for
that. `&Rw{Read,Write}LockGuard` only provides a shared referenced to `T`, sending
that across threads is safe if `T` is `Sync`.
Cc @oconnor663
rustbuild: don't try to install rls if ToolState is not Testing
We already do that for the Dist Step so we would end up trying to install something that we didn't dist.
Allow overriding the TLS model
This PR adds the ability to override the default "global-dynamic" TLS model with a more specific one through a target json option or a command-line option. This allows for better code generation in certain situations.
This is similar to the `-ftls-model=` option in GCC and Clang.
Guillaume Gomez
bors
Nick Cameron
Michael Hewson
Robin Kruppe
Kornel
Michael Woerister
kennytm
leonardo.yvens