They were only correct in the simplest case. Some of the optimisations
are certainly possible but should be introduced carefully and only
when the whole pattern codegen infrastructure is in a better shape.
Fixes#16648.
closes#16800
r? @nikomatsakis - I'm not 100% sure this is the right approach, it is kind of ad-hoc. The trouble is we don't have any intrinsic notion of which types are sized and which are not, we only have the Sized bound, so I have nothing to validate the Sized bound against.
Fixes#16597
I'm not 100% sure this is the correct way to handle this - but I wasn't able to find a better way without doing way more refactoring of the code that I was comfortable with. Comments and criticism are appreciated 😄
For example `let _x: &Trait = &*(box Foo as Box<Trait>);`. There was a bug where no cleanup would be scheduled by the deref.
No test because cleanup-auto-borrow-obj.rs is a test for this once we remove trait cross-borrowing (done on another branch).
Not sure if this is addressing the root cause or just patching up a symptom. Also not sure if I should be adding a diagnostic code for this.
Fixes#16750Fixes#15812
They were only correct in the simplest case. Some of the optimisations
are certainly possible but should be introduced carefully and only
when the whole pattern codegen infrastructure is in a better shape.
Fixes#16648.
Different Identifiers and Names can have identical textual representations, but different internal representations, due to the macro hygiene machinery (syntax contexts and gensyms). This provides a way to see these internals by compiling with `--pretty expanded,hygiene`.
This is useful for debugging & hacking on macros (e.g. diagnosing https://github.com/rust-lang/rust/issues/15750/https://github.com/rust-lang/rust/issues/15962 likely would've been faster with this functionality).
E.g.
```rust
#![feature(macro_rules)]
// minimal junk
#![no_std]
macro_rules! foo {
($x: ident) => { y + $x }
}
fn bar() {
foo!(x)
}
```
```rust
#![feature(macro_rules)]
// minimal junk
#![no_std]
fn bar /* 61#0 */() { y /* 60#2 */ + x /* 58#3 */ }
```
Fixes#12643
> Say!
> I like labelled breaks/continues!
I will use them with a `for` loop.
And I will use with a `loop` loop.
Say! I will use them ANYWHERE!
… _even_ in a `while` loop.
Because they're now supported there.
`--pretty expanded,hygiene` is helpful with debugging macro issues,
since two identifiers/names can be textually the same, but different
internally (resulting in weird "undefined variable" errors).
This adds support for lint groups to the compiler. Lint groups are a way of
grouping a number of lints together under one name. For example, this also
defines a default lint for naming conventions, named `bad_style`. Writing
`#[allow(bad_style)]` is equivalent to writing
`#[allow(non_camel_case_types, non_snake_case, non_uppercase_statics)]`. These
lint groups can also be defined as a compiler plugin using the new
`Registry::register_lint_group` method.
This also adds two built-in lint groups, `bad_style` and `unused`. The contents
of these groups can be seen by running `rustc -W help`.
This unifies the `non_snake_case_functions` and `uppercase_variables` lints
into one lint, `non_snake_case`. It also now checks for non-snake-case modules.
This also extends the non-camel-case types lint to check type parameters, and
merges the `non_uppercase_pattern_statics` lint into the
`non_uppercase_statics` lint.
Because the `uppercase_variables` lint is now part of the `non_snake_case`
lint, all non-snake-case variables that start with lowercase characters (such
as `fooBar`) will now trigger the `non_snake_case` lint.
New code should be updated to use the new `non_snake_case` lint instead of the
previous `non_snake_case_functions` and `uppercase_variables` lints. All use of
the `non_uppercase_pattern_statics` should be replaced with the
`non_uppercase_statics` lint. Any code that previously contained non-snake-case
module or variable names should be updated to use snake case names or disable
the `non_snake_case` lint. Any code with non-camel-case type parameters should
be changed to use camel case or disable the `non_camel_case_types` lint.
[breaking-change]
The inference scheme proposed in <http://smallcultfollowing.com/babysteps/blog/2014/07/09/an-experimental-new-type-inference-scheme-for-rust/>.
This is theoretically a [breaking-change]. It is possible that you may encounter type checking errors, particularly related to closures or functions with higher-ranked lifetimes or object types. Adding more explicit type annotations should help the problem. However, I have not been able to make an example that *actually* successfully compiles with the older scheme and fails with the newer scheme.
f? @pcwalton, @pnkfelix
