A Surprising Enum Size Optimization in Rust
2025-04-10
The Rust compiler employs a clever memory optimization for enums, reducing their size and boosting performance. The article analyzes the in-memory representation of enums, revealing two optimization strategies: the 'niche optimization,' using invalid bit patterns for variants without payloads; and an optimization for nested enums, cleverly reusing the inner enum's memory layout to minimize the outer enum's size. Both strategies significantly reduce memory consumption, improving program efficiency.
Read more
Development