I have this code, for learning purposes:
struct Fibonacci { curr: u32, next: u32, } impl Iterator for Fibonacci { type Item = u32; fn next(&mut self) -> Option<Self::Item> { let current = self.curr; self.curr = self.next; self.next = current + self.next; Some(current) } } impl Fibonacci { fn new() -> Self { Fibonacci { curr: 0, next: 1 } } fn current(&self) -> u32 { self.curr } } fn main() { println!("The first four terms of the Fibonacci sequence are: "); let fib = Fibonacci::new(); for i in fib.take(4) { println!("> {}", i); } // println!("cur {}", fib.current()); // *fails* } Here fib.take(4) consumes the fib value, so the commented out println below the loop doing fib.current() fails , quite naturally, with:
let fib = Fibonacci::new(); --- move occurs because `fib` has type `Fibonacci`, which does not implement the `Copy` trait for i in fib.take(4) { ------- `fib` moved due to this method call ... println!("cur {}", fib.current()); ^^^^^^^^^^^^^ value borrowed here after move note: this function takes ownership of the receiver `self`, which moves `fib` How would I implement the code above such that the Iterator does not consume it's value, and I can use the fib variable after the loop ?
