try_collect into Option<Vec<T>>

[tqwewe]

Given a stream of Result<Option<T>>, I'd like to .try_collect into an Option<Vec<T>>, but it seems like this is not supported.

Is there any obvious reason for this?

Currently my workaround is:

let workers = ...; // some stream of Result<Option<T>>

let items = workers
  .try_collect::<Vec<_>>()
  .await?
  .into_iter()
  .collect::<Option<Vec<_>>>();

Or a manual while loop pushing to a vec.

[taiki-e]

Duplicate of #1833.