---

name: maverick-rust-performance description: Rust performance optimization and zero-cost abstractions version: 1.0.0 triggers:

• clone
• to_owned
• Vec::with_capacity
• String::with_capacity
• iter()
• collect()
• performance
• optimize
• allocation

---

Rust Performance Skill

Avoid Unnecessary Clones

Copy// BAD
fn process(s: String) -> String {
    let s_copy = s.clone();  // Unnecessary!
    s_copy.to_uppercase()
}

// GOOD
fn process(s: String) -> String {
    s.to_uppercase()
}

// OR borrow if you don't need ownership
fn process(s: &str) -> String {
    s.to_uppercase()
}

Preallocate Collections

Copy// BAD - many reallocations
let mut vec = Vec::new();
for i in 0..1000 {
    vec.push(i);
}

// GOOD - single allocation
let vec: Vec<_> = (0..1000).collect();

// OR with_capacity
let mut vec = Vec::with_capacity(1000);

Zero-Cost Abstractions

Iterators are as fast as loops due to inlining and optimization.

Review Severity

• MAJOR: Unnecessary clones in hot path
• MINOR: Could preallocate collection
• SUGGESTION: Could use iterator instead of loop