The State of Allocators in 2026 — 6 Months Later
Rust’s custom-allocator work is nearing stabilization, with a deliberately small initial Allocator surface for Vec and Box, planned dyn Allocator support, and stronger rules forbidding unwinding through allocator operations. The remaining complexity is mostly soundness: allocator cloning, drop behavior, Pin/memory covariance, and which container APIs can safely propagate allocator state. It is an MVP rather than a finished allocator ecosystem, but a meaningful step toward usable arena and domain-specific allocation in stable Rust.
The Lobsters submission had one comment and little disagreement; the article itself is the useful technical source.