Rust to Replace Pin with New Immovable Type System by 2027

The Rust project has accepted a strategic goal for 2026-2027 to introduce a new system of auto-traits designed to handle immovable types and guaranteed destructors. This initiative seeks to fundamentally change how the language manages memory relocation and resource cleanup, moving away from the current architecture used for self-referential data.

According to the official Rust project goals document, the proposal introduces three primary auto-traits: `Move`, which governs relocation in memory; `Destruct`, which handles implicit drops; and `Forget`, which controls the ability of a type to be forgotten via `mem::forget`. A central objective of this work is the introduction of the `Move` trait as a direct alternative to `Pin`. The project intends to eventually deprecate `Pin` entirely, as the current system encodes immovability as a property of the memory location rather than a property of the type itself.

The shift from Pin to types

Historically, Rust operated on the assumption that all types could be moved in memory and forgotten without running destructors. To support self-referential types that cannot be moved, the language introduced `Pin`. However, this created significant complexity and "duplicate definition" issues within trait signatures. The new approach follows the precedent of the "Sized hierarchy" work, which previously relaxed the assumption that all types must have a compile-time-known size. As the Rust Project Goals document states, "Rather than trying to change the language to make Pin work, we believe the problem is with Pin and we should improve the way immovable types are encoded in Rust instead."

Implications for systems and async

This transition to type-level properties will simplify how Rust handles complex systems-level patterns and resource management. Specifically, the `!Forget` trait would prevent types from being forgotten via `mem::forget`. By ensuring that destructors are guaranteed to run, the language can enable safe patterns such as scoped spawns for asynchronous tasks, which are currently difficult to implement safely.

Validation and timeline

To ensure these changes are viable in high-stakes environments, the project will validate the new traits through real-world testing within the Linux Kernel via the Rust for Linux project. This testing phase is critical for verifying that the new memory model meets the rigorous requirements of kernel-level development. The project has set the official timespan for achieving these goals between 2026 and 2027.