{
  "$type": "site.standard.document",
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  "path": "/t/what-is-allocator-by-ref-for/24356#post_7",
  "publishedAt": "2026-05-25T17:37:12.000Z",
  "site": "https://internals.rust-lang.org",
  "tags": [
    "Add a \"by reference\" adaptor for `AllocRef` by TimDiekmann · Pull Request #71442 · rust-lang/rust · GitHub",
    "The issue mentions"
  ],
  "textContent": "That’s not a good reason to have it for `Allocator`, though. I can see that someone might want to pass `&MyAllocator` when constructing a container, but that will never be a method chain.\n\nAccording to the revision history, `by_ref` was added in Add a \"by reference\" adaptor for `AllocRef` by TimDiekmann · Pull Request #71442 · rust-lang/rust · GitHub, which was primarily about adding the `&A` (at the time, `&mut A`) implementation. The issue mentions adding `by_ref` by analogy with `io::Write::by_ref()`. Which seems to me to be a method with equally little reason to exist, but perhaps I am missing something.",
  "title": "What is Allocator::by_ref for?"
}