Rust 1.95 Adds `cfg_select!`, Extends `if let` Guards, and Tightens Stable Target Handling

Overview

Rust 1.95 shipped on April 16, 2026, adding a new cfg_select! macro, extending if let guards into match expressions, and stabilizing a long list of APIs, according to the Rust release announcement. This follows our March coverage of Rust 1.94 and shows the language keeping up a rapid release cadence.

What Changed

cfg_select! is Rust’s new compile-time branching macro for configuration predicates, and the Rust team says it serves the same use case as the cfg-if crate while keeping the syntax in the standard language surface, according to the release announcement. Rust 1.95 also brings if let guards into match arms, so code can combine pattern matching and conditional checks in one expression, according to the Rust team.

The release also stabilizes several API families, including MaybeUninit conversions, Atomic*::update helpers, Vec::push_mut, and new core::range items, according to the release announcement. In the same release, fmt::from_fn, ControlFlow::is_break, and ControlFlow::is_continue become stable in const contexts, according to the Rust team.

Why It Matters

The practical value of cfg_select! is that it reduces the amount of bespoke #[cfg(...)] scaffolding needed in portable code, while keeping configuration branching readable and local to the expression being selected, according to the Rust release announcement. The release also draws a harder line on advanced build setups by removing stable support for passing custom target JSON specifications to rustc, while the Rust team says it is still collecting use cases for possible future stabilization, according to the same announcement.

That change was already forcing downstream work before the release shipped. On February 21, Phoronix reported that Linux 7.0 maintainers were preparing for Rust 1.95 by passing -Zunstable-options and fixing stricter compiler checks that the new release would enforce. The release team also said in its April 13 pre-release thread that Rust 1.95 was ready for testing ahead of the April 16 ship date, according to Rust Internals.

What We Don’t Know

Rust’s release notes say the team is still gathering use cases for custom targets, so it is not yet clear whether that capability returns in a different form or remains stable-only for now, according to the release announcement. It is also too early to know whether cfg_select! becomes a broadly adopted replacement for cfg-if or remains a convenience for codebases that already lean on the standard library’s configuration machinery; that is an inference based on the feature’s current stabilization status and the crate the Rust team chose to cite.