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fuchsia / third_party / rust / 2de2456fb7b2b55cb104bb03f30edd145c6015a3
commit2de2456fb7b2b55cb104bb03f30edd145c6015a3[log] [tgz]
authorbors <bors@rust-lang.org>Sat Aug 09 03:19:26 2025 +0000
committerbors <bors@rust-lang.org>Sat Aug 09 03:19:26 2025 +0000
tree0a7e1e293ad1b9e832d66bb9bcb2ebd6bab66d9d
parent4c7749e8c8e50ad146da599eea3a250160c1bc2b [diff]
parent0bdaef5b63fe2d557483e72732e463b86ffb041b [diff]
Auto merge of #143376 - dianne:guard-scope, r=matthewjasper

add a scope for `if let` guard temporaries and bindings

This fixes my concern with `if let` guard drop order, namely that the guard's bindings and temporaries were being dropped after their arm's pattern's bindings, instead of before (https://github.com/rust-lang/rust/pull/141295#issuecomment-2968975596). The guard's bindings and temporaries now live in a new scope, which extends until (but not past) the end of the arm, guaranteeing they're dropped before the arm's pattern's bindings.

This only introduces a new scope for match arms with guards. Perf results (https://github.com/rust-lang/rust/pull/143376#issuecomment-3034922617) seemed to indicate there wasn't a significant hit to introduce a new scope on all match arms, but guard patterns (rust-lang/rust#129967) will likely benefit from only adding new scopes when necessary (with some patterns requiring multiple nested scopes).

Tracking issue for `if_let_guard`: rust-lang/rust#51114

Tests are adapted from examples by `@traviscross,` `@est31,` and myself on rust-lang/rust#141295.
tree: 0a7e1e293ad1b9e832d66bb9bcb2ebd6bab66d9d
  1. .github/
  2. compiler/
  3. library/
  4. LICENSES/
  5. src/
  6. tests/
  7. .clang-format
  8. .editorconfig
  9. .git-blame-ignore-revs
  10. .gitattributes
  11. .gitignore
  12. .gitmodules
  13. .ignore
  14. .mailmap
  15. bootstrap.example.toml
  16. Cargo.lock
  17. Cargo.toml
  18. CODE_OF_CONDUCT.md
  19. configure
  20. CONTRIBUTING.md
  21. COPYRIGHT
  22. INSTALL.md
  23. LICENSE-APACHE
  24. license-metadata.json
  25. LICENSE-MIT
  26. package-lock.json
  27. package.json
  28. README.md
  29. RELEASES.md
  30. REUSE.toml
  31. rust-bors.toml
  32. rustfmt.toml
  33. triagebot.toml
  34. typos.toml
  35. x
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README.md

Website | Getting started | Learn | Documentation | Contributing

This is the main source code repository for Rust. It contains the compiler, standard library, and documentation.

Why Rust?

  • Performance: Fast and memory-efficient, suitable for critical services, embedded devices, and easily integrated with other languages.

  • Reliability: Our rich type system and ownership model ensure memory and thread safety, reducing bugs at compile-time.

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