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fuchsia / third_party / github.com / rust-lang / rust-analyzer / 4f0658f5d334ea22067a48b9c16bf63f37f45f6f
commit4f0658f5d334ea22067a48b9c16bf63f37f45f6f[log] [tgz]
authorAlex Butler <alexheretic@gmail.com>Sun Sep 14 00:36:31 2025 +0100
committerLukas Wirth <me@lukaswirth.dev>Mon Sep 22 21:07:17 2025 +0200
tree2b4016b72db798d447b3d4671d5136686f8602a2
parent0e432a0b7c1f537d3bdafd1ec2afb103745b15ec [diff]
Optimise to_ascii_{upper,lower}case_smolstr
1 file changed
tree: 2b4016b72db798d447b3d4671d5136686f8602a2
  1. .github/
  2. src/
  3. tests/
  4. .gitignore
  5. bors.toml
  6. Cargo.toml
  7. CHANGELOG.md
  8. LICENSE-APACHE
  9. LICENSE-MIT
  10. README.md
README.md

smol_str

CI Crates.io API reference

A SmolStr is a string type that has the following properties:

  • size_of::<SmolStr>() == 24 (therefore == size_of::<String>() on 64 bit platforms)
  • Clone is O(1)
  • Strings are stack-allocated if they are:
    • Up to 23 bytes long
    • Longer than 23 bytes, but substrings of WS (see src/lib.rs). Such strings consist solely of consecutive newlines, followed by consecutive spaces
  • If a string does not satisfy the aforementioned conditions, it is heap-allocated
  • Additionally, a SmolStr can be explicitly created from a &'static str without allocation

Unlike String, however, SmolStr is immutable. The primary use case for SmolStr is a good enough default storage for tokens of typical programming languages. Strings consisting of a series of newlines, followed by a series of whitespace are a typical pattern in computer programs because of indentation. Note that a specialized interner might be a better solution for some use cases.

MSRV Policy

Minimal Supported Rust Version: latest stable.

Bumping MSRV is not considered a semver-breaking change.