Tracking Issue for `strip_circumfix`

Feature gate: #![feature(strip_circumfix)]

This is a tracking issue for adding the strip_circumfix method to str and the slice primitives.

These methods are a shorter and more concise way to express these prevalent patterns that appear in a lot of code:

if let Some(a) = a.strip_prefix('<') && let Some(a) = a.strip_suffix('>') {}

// or...

let a = a.strip_prefix('<').and_then(|a| a.strip_suffix('>'));

Public API

impl str {
    pub fn strip_circumfix<P: Pattern, S: Pattern>(&self, prefix: P, suffix: S) -> Option<&str>
    where
        for<'a> S::Searcher<'a>: ReverseSearcher<'a>;
}

impl<T> [T] {
    pub fn strip_circumfix(&self, prefix: &P, suffix: &S) -> Option<&[T]>
    where
        P: SlicePattern<Item = T> + ?Sized,
        S: SlicePattern<Item = T> + ?Sized,
        T: PartialEq;
}

Steps / History

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

• ACP: rust-lang/libs-team#680
• Implementation: #147947
• Final comment period (FCP)^1
• Stabilization PR

Unresolved Questions

• Is this too niche? https://hackmd.io/-3EwglvOR2W-jXGyPEoUXQ#new-change-proposal-rusttflibs680-strslicestrip_affixes

Review the public API and the completed implementation in #147947, then read the stabilization guidance linked in the issue. Check the unresolved question about whether the feature is too niche and verify the required release-cycle and FCP conditions. Done means opening or completing the stabilization PR once no blocking concerns remain.