{
  "$type": "site.standard.document",
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  "path": "/t/introduce-a-way-to-construct-range-from-start-length/24073#post_21",
  "publishedAt": "2026-03-13T16:46:59.000Z",
  "site": "https://internals.rust-lang.org",
  "tags": [
    "github.com/rust-lang/rfcs",
    "Extending deref/index with ownership transfer: DerefMove, IndexMove, IndexSet",
    "nikomatsakis"
  ],
  "textContent": "This could be added motivation for `IndexMove` / `IndexGet`:\n\ngithub.com/rust-lang/rfcs\n\n####  Extending deref/index with ownership transfer: DerefMove, IndexMove, IndexSet\n\nopened 11:03AM - 21 Mar 15 UTC\n\n nikomatsakis \n\nT-lang  T-libs-api\n\nIt is clear that there is a need for the ability to move out of smart pointers a…nd indexable things (`DerefMove`, `IndexMove`). The other frequently desired option is to `IndexSet`, which would be a special-cased version for indexing in this situation: ``` map[key] = value ``` currently, this is handled via `IndexMut`, but that is sub-optimal, because if the `key` is not already part of the `map`, the result is a panic. ### Basic plan DerefMove/IndexMove/IndexSet should layer on top of the traits we have now. One needs to be careful here because of subtle interactions with autoref and so forth. ### Postponed RFCs - https://github.com/rust-lang/rfcs/pull/178 - https://github.com/rust-lang/rfcs/pull/159 - https://github.com/rust-lang/rfcs/pull/1129 (`map[key] = value`)",
  "title": "Introduce a way to construct Range from start + length"
}