Rust Platform

🎯 In Python, function signatures don't constrain what types are allowed:

def largest(items):
    return max(items)  # works if items support comparison, crashes if not

largest([3, 1, 4])       # 4
largest(["a", "c", "b"]) # "c"
largest([{}, {}])         # TypeError at runtime

You find out about type mismatches when the code runs. Type hints help, but they're advisory:

from typing import TypeVar
T = TypeVar("T", bound=Comparable)

def largest(items: list[T]) -> T:
    return max(items)

Rust's trait bounds serve the same purpose — but they're enforced by the compiler. If a type doesn't meet the bounds, the code won't compile.

Basic bounds

A trait bound constrains a type parameter to types that implement specific traits:

fn print_it<T: Display>(item: T) {
    println!("{}", item);
}

T: Display means "T must implement Display." You …