Stumbled across this and thought it would be cool to prove. I've never used Ogden's Lemma before, but I'm pretty sure I used it right. The pumping lemma definitely doesn't seem sufficient for the job. In particular, when using the pumping lemma, you can always just pump one of the quotes, and it's fine. Ogden's Lemma lets you effectively force the pumper to use certain characters in the string.
@cmr
Everyone agreed except @thestinger. As @thestinger contribution on this file is trivial,
we can relicense it.
Related to #14248, close#15330
@brson OK?
This commit applies stability attributes to the contents of these modules,
summarized here:
* The `unit` and `bool` modules have become #[unstable] as they are purely meant
for documentation purposes and are candidates for removal.
* The `ty` module has been deprecated, and the inner `Unsafe` type has been
renamed to `UnsafeCell` and moved to the `cell` module. The `marker1` field
has been removed as the compiler now always infers `UnsafeCell` to be
invariant. The `new` method i stable, but the `value` field, `get` and
`unwrap` methods are all unstable.
* The `tuple` module has its name as stable, the naming of the `TupleN` traits
as stable while the methods are all #[unstable]. The other impls in the module
have appropriate stability for the corresponding trait.
* The `arc` module has received the exact same treatment as the `rc` module
previously did.
* The `any` module has its name as stable. The `Any` trait is also stable, with
a new private supertrait which now contains the `get_type_id` method. This is
to make the method a private implementation detail rather than a public-facing
detail.
The two extension traits in the module are marked #[unstable] as they will not
be necessary with DST. The `is` method is #[stable], the as_{mut,ref} methods
have been renamed to downcast_{mut,ref} and are #[unstable].
The extension trait `BoxAny` has been clarified as to why it is unstable as it
will not be necessary with DST.
This is a breaking change because the `marker1` field was removed from the
`UnsafeCell` type. To deal with this change, you can simply delete the field and
only specify the value of the `data` field in static initializers.
[breaking-change]
This commit applies stability attributes to the contents of these modules,
summarized here:
* The `unit` and `bool` modules have become #[unstable] as they are purely meant
for documentation purposes and are candidates for removal.
* The `ty` module has been deprecated, and the inner `Unsafe` type has been
renamed to `UnsafeCell` and moved to the `cell` module. The `marker1` field
has been removed as the compiler now always infers `UnsafeCell` to be
invariant. The `new` method i stable, but the `value` field, `get` and
`unwrap` methods are all unstable.
* The `tuple` module has its name as stable, the naming of the `TupleN` traits
as stable while the methods are all #[unstable]. The other impls in the module
have appropriate stability for the corresponding trait.
* The `arc` module has received the exact same treatment as the `rc` module
previously did.
* The `any` module has its name as stable. The `Any` trait is also stable, with
a new private supertrait which now contains the `get_type_id` method. This is
to make the method a private implementation detail rather than a public-facing
detail.
The two extension traits in the module are marked #[unstable] as they will not
be necessary with DST. The `is` method is #[stable], the as_{mut,ref} methods
have been renamed to downcast_{mut,ref} and are #[unstable].
The extension trait `BoxAny` has been clarified as to why it is unstable as it
will not be necessary with DST.
This is a breaking change because the `marker1` field was removed from the
`UnsafeCell` type. To deal with this change, you can simply delete the field and
only specify the value of the `data` field in static initializers.
[breaking-change]
Add `check-secondary`, which runs the pretty and lexer tests so we can run them on a dedicated bot. Leaves the pretty tests running under `check` until the bots are switched over. Also fixes some issues.
r? @cmr
Rename and gensym the runtime on import, so that users
can't refer to the `native` crate.
This is unlikely to break code, but users should import the "native" crate directly.
[breaking-change]
cc @alexcrichton
Sadly there's still a lot of open issues, but this tackles some of the more pressing ones. Each commit has its own description along with the issues it closes.
Currently we don't emit lifetime end markers when translating the
unwinding code. I omitted that when I added the support for lifetime
intrinsics, because I initially made the mistake of just returning true
in clean_on_unwind(). That caused almost all calls to be translated as
invokes, leading to quite awful results.
To correctly emit the lifetime end markers, we must differentiate
between cleanup that requires unwinding and such cleanup that just wants
to emit code during unwinding.
This is super, super WIP, but I'm going to go get lunch for a while, and figured I'd toss my work up here in case anyone wants to see my work as I do it.
This contains a new introductory section explaining the basics of pointers, and some pitfalls that Rust attempts to solve. I'd be interested in hearing how my explanation is, as well as if this belongs here. Pointers are such a crucial concept, I don't mind having a beginners' section on them in the main docs, even though our main audience is supposed to understand them already. Reasonable people may disagree, however.
Add an example showing how to use the map with a custom type. Fill in
examples for methods without ones.
Also move `pop_equiv` next to related public methods, to not create a
duplicate trait in the docs.
the CFG for match statements.
There were two bugs in issue #14684. One was simply that the borrow
check didn't know about the correct CFG for match statements: the
pattern must be a predecessor of the guard. This disallows the bad
behavior if there are bindings in the pattern. But it isn't enough to
prevent the memory safety problem, because of wildcards; thus, this
patch introduces a more restrictive rule, which disallows assignments
and mutable borrows inside guards outright.
I discussed this with Niko and we decided this was the best plan of
action.
This breaks code that performs mutable borrows in pattern guards. Most
commonly, the code looks like this:
impl Foo {
fn f(&mut self, ...) {}
fn g(&mut self, ...) {
match bar {
Baz if self.f(...) => { ... }
_ => { ... }
}
}
}
Change this code to not use a guard. For example:
impl Foo {
fn f(&mut self, ...) {}
fn g(&mut self, ...) {
match bar {
Baz => {
if self.f(...) {
...
} else {
...
}
}
_ => { ... }
}
}
}
Sometimes this can result in code duplication, but often it illustrates
a hidden memory safety problem.
Closes#14684.
[breaking-change]
Rename and gensym the runtime on import, so that users
can't refer to the `native` crate.
This is unlikely to break code, but users should import the "native" crate directly.
[breaking-change]
I'm not entirely sure if the correct space can be inferred when cleaning
Generics, so the impl has been switched to take the space explicitly.
Closes#15099
