Tracking Issue for `core::cell::{Ref,RefMut}::try_map`

Feature gate: #![feature(refcell_try_map)]

This is a tracking issue for core::cell::{Ref,RefMut}::try_map

Public API

impl<'b, T> Ref<'b, T> {
    pub fn try_map<U: ?Sized, E>(
        orig: Ref<'b, T>,
        f: impl FnOnce(&T) -> Result<&U, E>,
    ) -> Result<Ref<'b, U>, (Self, E)> ;
}

impl<'b, T> RefMut<'b, T> {
    pub fn try_map<U: ?Sized, E>(
        mut orig: RefMut<'b, T>,
        f: impl FnOnce(&mut T) -> Result<&mut U, E>,
    ) -> Result<RefMut<'b, U>, (Self, E)>;
}

Steps / History

(Remember to update the S-tracking-* label when checking boxes.)

• Implementation: #118087
• First ACP: https://github.com/rust-lang/libs-team/issues/341 (ignored by t-libs-api for 17 months)
• Second ACP: https://github.com/rust-lang/libs-team/issues/586 (accepted within 10 days, lol)
• Separate error type: #153093
• Expanding to cover more types: TBD
• Final comment period (FCP)^1
• Stabilization PR: #152092

Unresolved Questions

• None yet.

Begin with the public API shown in the issue and review the linked implementation, ACPs, separate-error issue, and stabilization PR. Done is the completion of the remaining checklist items, including the final comment period and stabilization; the issue currently lists no unresolved questions.