Rust 1.23.0, announced January 4, 2018, reports a 5–10% drop in memory use for rustc in certain situations after unnecessary copies were reduced. The Rust team cautioned that the result may differ in individual programs. For developers maintaining builds, lower compiler memory use could ease one resource pressure; the announcement does not quantify effects on teams’ hardware or budgets. [shared-c478f061316439025da482439e7562cedce9703fa8e2eee9f582cc21eee0db7a]
The release also begins a documentation transition. Rustdoc now checks pages with both its previous Hoedown renderer and a CommonMark-compliant renderer, warning when their output differs. CommonMark was planned to become the default in a future release, so maintainers had notice of a coming format change—not confirmation that it had already happened. Cargo’s documentation moved from doc.crates.io to doc.rust-lang.org/cargo, with a redirect still planned. [shared-c478f061316439025da482439e7562cedce9703fa8e2eee9f582cc21eee0db7a]
Other changes include direct ASCII methods on relevant types, new conversions for atomic types, and the ability for cargo check to check unit tests; cargo uninstall can remove multiple packages in one command. These additions offer practical conveniences, but the release note provides no measure of adoption or time saved. The open question is whether the renderer warnings make the migration manageable for documentation authors before CommonMark becomes the default. [shared-c478f061316439025da482439e7562cedce9703fa8e2eee9f582cc21eee0db7a]