Comparison with C - Rust for C-Programmers

6.10 Comparison with C Memory Management

6.10.1 Memory Safety Guarantees

Rust prevents many problems typical in C:

Memory Leaks: Data is freed automatically when owners leave scope.
Dangling Pointers: The borrow checker disallows references to freed data.
Double Frees: Ownership rules ensure you cannot free the same resource twice.
Buffer Overflows: Slices with built-in checks greatly reduce out-of-bounds writes.

6.10.2 Concurrency Safety

Rust’s ownership model streamlines safe data sharing across threads. Traits such as Send and Sync enforce compile-time concurrency checks:

use std::thread;

fn main() {
    let s = String::from("hello");
    let handle = thread::spawn(move || {
        println!("{}", s);
    });
    handle.join().unwrap();
}

Types that implement Send can be transferred between threads, and Sync ensures a type can be safely accessed by multiple threads.

6.10.3 Zero-Cost Abstractions

Despite these safety features, Rust typically compiles down to very efficient code, often matching or even exceeding the performance of similar C implementations.