--- title: "Niches for integer types in Rust" url: https://daily.dev/posts/niches-for-integer-types-in-rust-grufxq4r3 source_url: https://deterministic.space/niche-int-types-in-rust.html type: article source: "Pascal’s scribbles" published: 2026-05-04T16:40:50.182Z updated: 2026-05-04T16:41:14.535Z tags: ["rust"] reading_time: 5 upvotes: 3 comments: 0 language: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Niches for integer types in Rust **[Pascal’s scribbles](https://daily.dev/sources/deterministicspace)** · 5 min read · 3 upvotes · 0 comments ## Summary Explores how to create memory-efficient integer wrapper types in Rust using type niches. Starting with a DNA sequence position type (Pos) that only uses the u31 range, the post covers three approaches: a naive u32 wrapper (wastes 4 bytes in Option), the NonZero bias trick on stable Rust (stores value+1 to expose a niche, making Option 4 bytes), and the experimental nightly pattern_type! macro that lets you declare a valid range directly (e.g., i32 is 0..=i32::MAX). The nightly approach is cleaner conceptually but requires unsafe transmute for now. The post also notes that the older rustc_layout_scalar_valid_range_start attributes are being replaced by pattern types. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: --- Tags: [#rust](https://daily.dev/tags/rust) [View this post on daily.dev](https://daily.dev/posts/niches-for-integer-types-in-rust-grufxq4r3)