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A surprising enum size optimization in the Rust compiler

a year ago
  • #Enums
  • #Memory Optimization
  • #Rust
  • Enums in Rust are types with a set of variants, like `Foo` which can be `Int(u32)` or `Char(char)`.
  • The size of an enum is typically the size of its largest variant plus a tag to identify the variant.
  • Rust optimizes enum memory usage, such as the niche optimization for enums like `Option<char>`.
  • Nested enums (`Outer` containing `Inner`) can share memory representation, reducing overall size.
  • Memory representation can be inspected using functions like `print_memory_representation`.