This squashes the
> `for` loop expression has type `[type error]` which does not implement
> the `Iterator` trait
message that one received when writing `for ... in x` where was
previously found to have a type error.
Fixes#16042.
Per API meeting
https://github.com/rust-lang/meeting-minutes/blob/master/Meeting-API-review-2014-08-13.md
# Changes to `core::option`
Most of the module is marked as stable or unstable; most of the unstable items are awaiting resolution of conventions issues.
However, a few methods have been deprecated, either due to lack of use or redundancy:
* `take_unwrap`, `get_ref` and `get_mut_ref` (redundant, and we prefer for this functionality to go through an explicit .unwrap)
* `filtered` and `while`
* `mutate` and `mutate_or_set`
* `collect`: this functionality is being moved to a new `FromIterator` impl.
# Changes to `core::result`
Most of the module is marked as stable or unstable; most of the unstable items are awaiting resolution of conventions issues.
* `collect`: this functionality is being moved to a new `FromIterator` impl.
* `fold_` is deprecated due to lack of use
* Several methods found in `core::option` are added here, including `iter`, `as_slice`, and variants.
Due to deprecations, this is a:
[breaking-change]
DST coercions and DST fields in structs
The commits are not quite stand alone, I should probably squash them together before landing. In particular if you review the individual commits, then you'll see some scrappy stuff that gets fixed in later commits. But reading the commits in order might be easier to get an overall idea of what is going on.
The first commit includes putting back time zone into our time library - @pcwalton removed that as part of his de-~str'ing, but I had already converted it to use StrBuf, so we may as well leave it in. Update: no longer, this is removed in a later commit.
[breaking-change]
1. The internal layout for traits has changed from (vtable, data) to (data, vtable). If you were relying on this in unsafe transmutes, you might get some very weird and apparently unrelated errors. You should not be doing this! Prefer not to do this at all, but if you must, you should use raw::TraitObject rather than hardcoding rustc's internal representation into your code.
2. The minimal type of reference-to-vec-literals (e.g., `&[1, 2, 3]`) is now a fixed size vec (e.g., `&[int, ..3]`) where it used to be an unsized vec (e.g., `&[int]`). If you want the unszied type, you must explicitly give the type (e.g., `let x: &[_] = &[1, 2, 3]`). Note in particular where multiple blocks must have the same type (e.g., if and else clauses, vec elements), the compiler will not coerce to the unsized type without a hint. E.g., `[&[1], &[1, 2]]` used to be a valid expression of type '[&[int]]'. It no longer type checks since the first element now has type `&[int, ..1]` and the second has type &[int, ..2]` which are incompatible.
3. The type of blocks (including functions) must be coercible to the expected type (used to be a subtype). Mostly this makes things more flexible and not less (in particular, in the case of coercing function bodies to the return type). However, in some rare cases, this is less flexible. TBH, I'm not exactly sure of the exact effects. I think the change causes us to resolve inferred type variables slightly earlier which might make us slightly more restrictive. Possibly it only affects blocks with unreachable code. E.g., `if ... { fail!(); "Hello" }` used to type check, it no longer does. The fix is to add a semicolon after the string.
The privacy pass of the compiler was previously not taking into account the
privacy of foreign items, or bindings to external functions. This commit fixes
this oversight by encoding the visibility of foreign items into the metadata for
each crate.
Any code relying on this will start to fail to compile and the bindings must be
marked with `pub` to indicate that they can be used externally.
Closes#16725
[breaking-change]
Current version of rust fails when casting from bool, e.g.
```rust
fn main() {
let _a = false as uint;
let _b = true as uint;
let _c: [bool, ..false as uint];
let _d: [bool, ..true as uint];
// _a and _b work, but _c and _d result in an error
// error: expected constant expr for vector length: can't cast str to uint
}
```
This commit makes it work as expected.
int/uint aren't considered FFI safe, replace them with the actual type they
represent (i64/u64 or i32/u32). This is a breaking change, but at most a cast
to `uint` or `int` needs to be added.
[breaking-change]
As of RFC 18, struct layout is undefined. Opting into a C-compatible struct
layout is now down with #[repr(C)]. For consistency, specifying a packed
layout is now also down with #[repr(packed)]. Both can be specified.
To fix errors caused by this, just add #[repr(C)] to the structs, and change
#[packed] to #[repr(packed)]
Closes#14309
[breaking-change]
It's unfortunate that the read+write operands need special treatment in the AST. A separate vec for all expressions is an alternative, but it doesn't play nicely with trans.
Fixes#14936
Stop read+write expressions from expanding into two occurences
in the AST. Add a bool to indicate whether an operand in output
position if read+write or not.
Fixes#14936
This is enough for dynamic libraries, but not executables because MinGW
does not output a .reloc section even with `--dynamicbase`. It could
either be worked around by exporting a DLL symbol from the executable or
fixed in MinGW itself.
This is enough for dynamic libraries, but not executables because MinGW
does not output a .reloc section even with `--dynamicbase`. It could
either be worked around by exporting a DLL symbol from the executable or
fixed in MinGW itself.
declared with the same name in the same scope.
This breaks several common patterns. First are unused imports:
use foo::bar;
use baz::bar;
Change this code to the following:
use baz::bar;
Second, this patch breaks globs that import names that are shadowed by
subsequent imports. For example:
use foo::*; // including `bar`
use baz::bar;
Change this code to remove the glob:
use foo::{boo, quux};
use baz::bar;
Or qualify all uses of `bar`:
use foo::{boo, quux};
use baz;
... baz::bar ...
Finally, this patch breaks code that, at top level, explicitly imports
`std` and doesn't disable the prelude.
extern crate std;
Because the prelude imports `std` implicitly, there is no need to
explicitly import it; just remove such directives.
The old behavior can be opted into via the `import_shadowing` feature
gate. Use of this feature gate is discouraged.
This implements RFC #116.
Closes#16464.
[breaking-change]
Crates that are resolved normally have their path canonicalized and all
symlinks resolved. This does currently not happen for paths specified
using the --extern option to rustc, which can lead to rustc thinking
that it encountered two different versions of a crate, when it's
actually the same version found through different paths.
Fixes#16496
These are already marked as `noalias` due to the immutability guarantee
(see 4c2d4cd3de), but more information can
be bubbled up to the caller via `readonly`.
When a struct implements Drop, its fields should still drop in
declaration order (just as they do when the struct does not implement
Drop).
Fixes#16492.
When a struct implements Drop, its fields should still drop in
declaration order (just as they do when the struct does not implement
Drop).
Fixes#16492.
The discriminant for Option values is either 0 or 1, so we can just
truncate the value to an i1, which ends up as a no-op for Options
containing pointers.
These are already marked as `noalias` due to the immutability guarantee
(see 4c2d4cd3de), but more information can
be bubbled up to the caller via `readonly`.
Crates that are resolved normally have their path canonicalized and all
symlinks resolved. This does currently not happen for paths specified
using the --extern option to rustc, which can lead to rustc thinking
that it encountered two different versions of a crate, when it's
actually the same version found through different paths.
To fix this, we must store the canonical path for crates found via
--extern and also use the canonical path when comparing paths.
Fixes#16496
The discriminant for Option values is either 0 or 1, so we can just
truncate the value to an i1, which ends up as a no-op for Options
containing pointers.
These `where` clauses are accepted everywhere generics are currently
accepted and desugar during type collection to the type parameter bounds
we have today.
A new keyword, `where`, has been added. Therefore, this is a breaking
change. Change uses of `where` to other identifiers.
[breaking-change]
r? @nikomatsakis (or whoever)
These `where` clauses are accepted everywhere generics are currently
accepted and desugar during type collection to the type parameter bounds
we have today.
A new keyword, `where`, has been added. Therefore, this is a breaking
change. Change uses of `where` to other identifiers.
[breaking-change]
methods.
This paves the way to associated items by introducing an extra level of
abstraction ("impl-or-trait item") between traits/implementations and
methods. This new abstraction is encoded in the metadata and used
throughout the compiler where appropriate.
There are no functional changes; this is purely a refactoring.
This patch primarily does two things: (1) it prevents lifetimes from
leaking out of unboxed closures; (2) it allows unboxed closure type
notation, call notation, and construction notation to construct closures
matching any of the three traits.
This breaks code that looked like:
let mut f;
{
let x = &5i;
f = |&mut:| *x + 10;
}
Change this code to avoid having a reference escape. For example:
{
let x = &5i;
let mut f; // <-- move here to avoid dangling reference
f = |&mut:| *x + 10;
}
I believe this is enough to consider unboxed closures essentially
implemented. Further issues (for example, higher-rank lifetimes) should
be filed as followups.
Closes#14449.
[breaking-change]
r? @pnkfelix
This patch primarily does two things: (1) it prevents lifetimes from
leaking out of unboxed closures; (2) it allows unboxed closure type
notation, call notation, and construction notation to construct closures
matching any of the three traits.
This breaks code that looked like:
let mut f;
{
let x = &5i;
f = |&mut:| *x + 10;
}
Change this code to avoid having a reference escape. For example:
{
let x = &5i;
let mut f; // <-- move here to avoid dangling reference
f = |&mut:| *x + 10;
}
I believe this is enough to consider unboxed closures essentially
implemented. Further issues (for example, higher-rank lifetimes) should
be filed as followups.
Closes#14449.
[breaking-change]
by-reference upvars.
This partially implements RFC 38. A snapshot will be needed to turn this
on, because stage0 cannot yet parse the keyword.
Part of #12381.
This required some contortions because importing both raw::Slice
and slice::Slice makes rustc crash.
Since `Slice` is in the prelude, this renaming is unlikely to
casue breakage.
[breaking-change]
