{
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"path": "/t/the-hashtable-problem-a-litmus-test-for-external-impl-proposals/24396#post_11",
"publishedAt": "2026-06-13T19:32:03.000Z",
"site": "https://internals.rust-lang.org",
"textContent": "I think the best answer is instead to add a level of indirection, not unlike we have with the buildhasher already.\n\nIf I use a `CustomizedBinaryHeap<MyCustomStrategy, T>` (where `BinaryHeap<T> = CustomizedBinaryHeap<DefaultOrdStrategy, T>`), then you can put any trait impl you want on your _local_ `MyCustomStrategy` type. So even if the `T` is some external type, that's fine.\n\nThat way the instances carry around the necessarily \"impls\" without needing all these extra features for adding new ways to specify things.",
"title": "The Hashtable Problem: A Litmus Test for External Impl Proposals"
}