Vec<T>
3 days ago
- #Rust
- #Memory Safety
- #Data Structures
- Vec<T> in Rust is built with multiple layers of abstraction for safety and efficiency.
- The structure starts with a raw pointer (*const u8) and is wrapped in NonNull<u8> to ensure it's never null.
- Unique<u8> adds ownership semantics, signaling sole ownership of the pointed data.
- RawVec<T> manages memory allocation, growth, and deallocation, separating capacity management from element tracking.
- Vec<T> combines RawVec (memory management) and len (tracking initialized elements) to provide a safe, user-friendly API.
- Each layer in Vec's structure serves a specific purpose, contributing to Rust's memory safety guarantees without runtime overhead.
- The design allows for reuse across the standard library, as seen in types like VecDeque<T>.
- Understanding Vec's internals reveals Rust's approach to combining low-level control with high-level safety.