Complete the set of Pin<->unpinned mut reference casts for incomplete types.

Supposing `Complete` is an `Unpin` type (the only time you'd run into this), and `Incomplete` is not (always true for incomplete types), then:

before:

* `Pin<&mut Incomplete>` -> `&mut Complete`

Now:

* `Pin<&mut Incomplete>` <-> `&mut Complete`
* `Pin<&mut Incomplete>` -> `&Complete`

PiperOrigin-RevId: 442816103
3 files changed
tree: b86d075530b74d206c66c3c3169a2d2ff83a5909
  1. cc_template/
  2. common/
  3. lifetime_annotations/
  4. rs_bindings_from_cc/
  5. BUILD
  6. CODE_OF_CONDUCT
  7. CONTRIBUTING
  8. LICENSE
  9. README.md
README.md

Crubit: C++/Rust Bidirectional Interop Tool

Extremely experimental interop tooling for C++ and Rust.

Please don‘t use, this is an experiment and we don’t yet know where will it take us. There will be breaking changes without warning. Unfortunately, we can't take contributions at this point.