Document eager evaluation of `bool::then_some` argument
I encountered this earlier today and thought maybe `bool::then_some` could use a little addition to the documentation.
It's pretty obvious with familiarity and from looking at the implementation, but the argument for `then_some` is eagerly evaluated, which means if you do the following (as I did), you can have a problem:
```rust
// Oops!
let _ = something
.has_another_thing()
.then_some(something.another_thing_or_panic());
```
A note, similar to other methods with eagerly-evaluated arguments and a lazy alternative (`Option::or`, for example), could help point this out to people who forget (like me)!
Suggest removing unnecessary prefix let in patterns
Helps with #101291, though I think `@estebank` probably wants this:
> Finally, I think it'd be nice if we could detect that we don't know for sure and "just" swallow the rest of the expression (find the next ; accounting for nested braces) or the end of the item (easier).
... to be implemented before we close that issue out completely.
Point out when a callable is not actually callable because its return is not sized
Fixes#100755
I didn't add a UI test for that one because it's equivalent to the UI test that already exists in the suite.
`BindingAnnotation` refactor
* `ast::BindingMode` is deleted and replaced with `hir::BindingAnnotation` (which is moved to `ast`)
* `BindingAnnotation` is changed from an enum to a tuple struct e.g. `BindingAnnotation(ByRef::No, Mutability::Mut)`
* Associated constants added for convenience `BindingAnnotation::{NONE, REF, MUT, REF_MUT}`
One goal is to make it more clear that `BindingAnnotation` merely represents syntax `ref mut` and not the actual binding mode. This was especially confusing since we had `ast::BindingMode`->`hir::BindingAnnotation`->`thir::BindingMode`.
I wish there were more symmetry between `ByRef` and `Mutability` (variant) naming (maybe `Mutable::Yes`?), and I also don't love how long the name `BindingAnnotation` is, but this seems like the best compromise. Ideas welcome.
`BindingAnnotation` refactor
* `ast::BindingMode` is deleted and replaced with `hir::BindingAnnotation` (which is moved to `ast`)
* `BindingAnnotation` is changed from an enum to a tuple struct e.g. `BindingAnnotation(ByRef::No, Mutability::Mut)`
* Associated constants added for convenience `BindingAnnotation::{NONE, REF, MUT, REF_MUT}`
One goal is to make it more clear that `BindingAnnotation` merely represents syntax `ref mut` and not the actual binding mode. This was especially confusing since we had `ast::BindingMode`->`hir::BindingAnnotation`->`thir::BindingMode`.
I wish there were more symmetry between `ByRef` and `Mutability` (variant) naming (maybe `Mutable::Yes`?), and I also don't love how long the name `BindingAnnotation` is, but this seems like the best compromise. Ideas welcome.
Don't duplicate file descriptors into stdio fds
Ensures that file descriptors are never duplicated into the stdio fds even if a stdio fd has been closed.
Revert "Mention rust-analyzer maintainers when `proc_macro` bridge is changed"
Reverts rust-lang/rust#99183
rust-analyzer is now a subtree, and CI fails when the `proc_macro` bridge changes break our tests, so these notifications aren't needed anymore.
Add a Machine hook for inline assembly
I'm sketching out some support in Miri to "execute" inline assembly. I want this because there are codebases which have very simple inline assembly like hand-written syscall wrappers, and it would be nice to test such code without modification.
r? ``@oli-obk``
Add let else drop order tests
Add a systematic matrix based test that checks temporary drop order in various settings, `let-else-drop-order.rs`, as requested [here](https://github.com/rust-lang/rust/pull/93628#issuecomment-1055738523).
The drop order of let and let else is supposed to be the and in order to ensure this, the test checks that this holds for a number of cases.
The test also ensures that we drop the temporaries of the condition before executing the else block.
cc #87335 tracking issue for `let else`
