Add special error for this case and help message `please recompile this crate using --crate-type lib`, also list found candidates.
See issue #14416
r? @alexcrichton
closes#21630
Overloaded indexing (`&[mut] foo[bar]`) only works when `<Self as Index>::Output` is the same as `<Self as IndexMut>::Output` (see issue above). To restrict implementations of `IndexMut` that doesn't work, this PR makes `IndexMut` a supertrait over `Index`, i.e. `trait IndexMut<I>: Index<I>`, just like in the `trait DerefMut: Deref` case.
This breaks all downstream implementations of `IndexMut`, in most cases this simply means removing the `type Output = ..` bit, which is now redundant, from `IndexMut` implementations:
``` diff
impl Index<Foo> for Bar {
type Output = Baz;
..
}
impl IndexMut<Foo> for Bar {
- type Output = Baz;
..
}
```
[breaking-change]
---
r? @nikomatsakis
are any where-clauses at all. This seems to be the simplest possible
rule and will (hopefully!) put an end to these annoying "cache leak"
bugs. Fixes#22019.
The compiler would previously fall back to using `-L` and normal lookup paths if
a `--extern` path was specified but it did not match (wrong architecture, for
example). This commit removes this behavior and forces the hand of the crate
loader to *always* use the `--extern` path if specified, no matter whether it is
correct or not.
This fixes a bug today where the compiler's own libraries are favored in cross
compilation by accident. For example when a crate using the crates.io version of
`log` was cross compiled, Cargo would compile `log` for the target architecture.
When loading the macros, however, the compiler currently favors using the *host*
architecture (for plugins), and because the `--extern log=...` pointed at an
rlib for the target architecture, that lookup failed. The crate loader then
fell back on `-L` paths to find the compiler-used `log` crate (the wrong one!)
and then a compile failure happened because the logging macros are slightly
different.
If you were still using `MaybeOwnedVector`, update your code to use `CowVec`.
[breaking-change]
---
We already removed `MaybeOwned` (the string equivalent) long time ago and with a much shorter deprecation period. It's time to let go.
(e.g., `Self::Output`)
This doesn't actually "resugar" qualified paths like `<Self as
Foo>::Output`, it just doesn't elide the prefix segments when rendering
cleaned paths like `Self::Output`.
cc #21145
....
The 'stable_features' lint helps people progress from unstable to
stable Rust by telling them when they no longer need a `feature`
attribute because upstream Rust has declared it stable.
This compares to the existing 'unstable_features' lint, which is used
to implement feature staging, and triggers on *any* use
of `#[feature]`.
This was particularly helpful in the time just after OIBIT's
implementation to make sure things that were supposed to be Copy
continued to be, but it's now creates a lot of noise for types that
intentionally don't want to be Copy.
r? @alexcrichton
Ported regions-mock-tcx to use TypedArena rather than Arena since it holds cyclic structure (which the Arena API updated for the Drop-Check-Rule cannot handle).
Plus, the use of `arena::Arena` here really is not justified; the allocated values are all the same type anyway.
Implement step 1 of rust-lang/rfcs#702
Allows the expression `..` (without either endpoint) in general, can be
used in slicing syntax `&expr[..]` where we previously wrote `&expr[]`.
The old syntax &expr[] is not yet removed or warned for.
In effect, temporary anonymous values created during the evaluation of
ITER_EXPR no longer not live for the entirety of the block surrounding
the for-loop; instead they only live for the extent of the for-loop
itself, and no longer.
----
There is one case I know of that this breaks, demonstrated to me by
niko (but it is also a corner-case that is useless in practice). Here
is that case:
```
fn main() {
let mut foo: Vec<&i8> = Vec::new();
for i in &[1, 2, 3] { foo.push(i) }
}
```
Note that if you add any code following the for-loop above, or even a
semicolon to the end of it, then the code will stop compiling (i.e.,
it gathers a vector of references but the gathered vector cannot
actually be used.)
(The above code, despite being useless, did occur in one run-pass test
by accident; that test is updated here to accommodate the new
striction.)
----
So, technically this is a:
[breaking-change]
This restructures tidy.py to walk the tree itself,
and improves performance considerably by not loading entire
files into buffers for licenseck.
Splits build rules into 'tidy', 'tidy-basic', 'tidy-binaries',
'tidy-errors', 'tidy-features'.
The 'stable_features' lint helps people progress from unstable to
stable Rust by telling them when they no longer need a `feature`
attribute because upstream Rust has declared it stable.
This compares to the existing 'unstable_features', which is used
to implement feature staging, and triggers on *any* use
of `#[feature]`.
Allows the expression `..` (without either endpoint) in general, can be
used in slicing syntax `&expr[..]` where we previously wrote `&expr[]`.
The old syntax &expr[] is not yet removed or warned for.
This was particularly helpful in the time just after OIBIT's
implementation to make sure things that were supposed to be Copy
continued to be, but it's now creates a lot of noise for types that
intentionally don't want to be Copy.
Currently, if a `#![staged_api]` crate contains an exported item without a stability marker (or inherited stability),
the item is useless.
This change introduces a check to ensure that all exported items have a defined stability.
it also introduces the `unmarked_api` feature, which lets users import unmarked features. While this PR should in theory forbid these from existing,
in practice we can't be so sure; so this lets users bypass this check instead of having to wait for the library and/or compiler to be fixed (since otherwise this is a hard error).
r? @aturon
This *almost* completes the job for #16440. The idea is that even if we do not know whether some closure type `C` implements `Fn` or `FnMut` (etc), we still know its argument and return types. So if we see an obligation `C : Fn(_0)`, we can unify `_0` with those argument types while still considering the obligation ambiguous and unsatisfied. This helps to make a lot of progress with type inference even before closure kind inference is done.
As part of this PR, the explicit `:` syntax is removed from the AST and completely ignored. We still infer the closure kind based on the expected type if that is available. There are several reasons for this. First, deciding the closure kind earlier is always better, as it allows us to make more progress. Second, this retains a (admittedly obscure) way for users to manually specify the closure kind, which is useful for writing tests if nothing else. Finally, there are still some cases where inference can fail, so it may be useful to have this manual override. (The expectation is that we will eventually revisit an explicit syntax for specifying the closure kind, but it will not be `:` and may be some sort of generalization of the `||` syntax to handle other traits as well.)
This commit does not *quite* fix#16640 because a snapshot is still needed to enable the obsolete syntax errors for explicit `&mut:` and friends.
r? @eddyb as he reviewed the prior patch in this direction
Implements [RFC 474](https://github.com/rust-lang/rfcs/pull/474); see
that RFC for details/motivation for this change.
This initial commit does not include additional normalization or
platform-specific path extensions. These will be done in follow up
commits or PRs.
Use the crates.io crate `rand` (version 0.1 should be a drop in
replacement for `std::rand`) and `rand_macros` (`#[derive_Rand]` should
be a drop-in replacement).
[breaking-change]
As part of [RFC 474](https://github.com/rust-lang/rfcs/pull/474), this
commit renames `std::path` to `std::old_path`, leaving the existing path
API in place to ease migration to the new one. Updating should be as
simple as adjusting imports, and the prelude still maps to the old path
APIs for now.
[breaking-change]
