rust-lang / rust-lang/rust

type-based search cannot find TryFrom<Vec<T>> for Box<[T; N]>

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C-bug needs-triage T-rustdoc
Dominant language
Rust
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Description

Code

Vec<T> -> Result<Box<_>, _>

Reproduction Steps

https://doc.rust-lang.org/stable/std/index.html?search=Vec%3CT%3E%20-%3E%20Result%3CBox%3C_%3E%2C%20_%3E

Expected Outcome

One of the hits includes:

https://doc.rust-lang.org/std/vec/struct.Vec.html#impl-TryFrom%3CVec%3CT%3E%3E-for-Box%3C%5BT;+N%5D%3E

Actual Output

"No results :("

Version

1.98.0
(88d9e12ae 2026-08-18)

1.100.0-nightly
(e7769602a 2026-08-24)

Additional Details

Trying a fuller version of the signature, Vec<T> -> Result<Box<[T; N]>, _>, gives a syntax error:

Query parser error: "Unexpected ; after T (not a valid identifier)".

That is probably #60485 and it not supporting arrays.

I am filing this as a separate bug, because even if array types cannot be entered in search terms, we should not deny the existence of functions with arrays in their types.

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start by reproducing the type-based search query on the linked stable or nightly rustdoc page and compare it with the expected TryFrom implementation URL. Trace the rustdoc search implementation and its handling of array types, then add or update coverage so the shorter query finds the implementation without rejecting array-containing signatures.

Written by the indexing model from the issue text.

Assessment

Tech stack
rust
Domain
documentation, search
Issue type
Bug
Difficulty
3/5
Estimated time
1-2 days
Activity status
Active
Clarity
Mostly clear
Newbie friendliness
68/100

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