Values Implementing Copy Remain Usable After Assignment

In Rust, integers do not behave like String during assignment, for example:

fn main() {
    let first = 42;
    let second = first;
 
    println!("{first}");
    println!("{second}");
}

This will compile perfectly fine because integers implement the Copy trait. We will understand about traits later in source

But in simple terms, Rust duplicates the value 42, so both variables remain usable. There is no shared heap allocation for the two variables. Copying the integer is also inexpensive because its size is small and fixed.

Common Copy types include integers, floating-point values, booleans, characters, shared references, and tuples contains only other Copy values