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fuchsia / third_party / github.com / rust-lang / rust / 44c7a2dbffef822bd8df3f154b37bf1bc51b1d9c
commit44c7a2dbffef822bd8df3f154b37bf1bc51b1d9c[log] [tgz]
authorLeón Orell Valerian Liehr <me@fmease.dev>Wed May 22 19:04:45 2024 +0200
committerGitHub <noreply@github.com>Wed May 22 19:04:45 2024 +0200
tree902ae271c5d39bd50f4fdaf3aa91962c6430b7d7
parent5b485f04dedef5d9eb69224c21d83f984017fc66 [diff]
parent2e97dae8d468623474d05dd84c270583ec3ed374 [diff]
Rollup merge of #125259 - compiler-errors:fn-mut-as-a-treat, r=oli-obk

An async closure may implement `FnMut`/`Fn` if it has no self-borrows

There's no reason that async closures may not implement `FnMut` or `Fn` if they don't actually borrow anything with the closure's env lifetime. Specifically, #123660 made it so that we don't always need to borrow captures from the closure's env.

See the doc comment on `should_reborrow_from_env_of_parent_coroutine_closure`:

https://github.com/rust-lang/rust/blob/c00957a3e269219413041a4e3565f33b1f9d0779/compiler/rustc_hir_typeck/src/upvar.rs#L1777-L1823

If there are no such borrows, then we are free to implement `FnMut` and `Fn` as permitted by our closure's inferred `ClosureKind`.

As far as I can tell, this change makes `async || {}` work in precisely the set of places they used to work before #120361.
Fixes #125247.

r? oli-obk
tree: 902ae271c5d39bd50f4fdaf3aa91962c6430b7d7
  1. .github/
  2. .reuse/
  3. compiler/
  4. library/
  5. LICENSES/
  6. src/
  7. tests/
  8. .editorconfig
  9. .git-blame-ignore-revs
  10. .gitattributes
  11. .gitignore
  12. .gitmodules
  13. .mailmap
  14. Cargo.lock
  15. Cargo.toml
  16. CODE_OF_CONDUCT.md
  17. config.example.toml
  18. configure
  19. CONTRIBUTING.md
  20. COPYRIGHT
  21. INSTALL.md
  22. LICENSE-APACHE
  23. LICENSE-MIT
  24. README.md
  25. RELEASES.md
  26. rust-bors.toml
  27. rustfmt.toml
  28. triagebot.toml
  29. x
  30. x.ps1
  31. x.py
README.md

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