rust by example指南显示了带迭代器的斐波那契数列的以下代码here:
fn next(&mut self) -> Option<u32> {
let new_next = self.curr + self.next;
let new_curr = mem::replace(&mut self.next, new_next);
// 'Some' is always returned, this is an infinite value generator
Some(mem::replace(&mut self.curr, new_curr))
}
我想了解与最直观的(如果你来自其他语言)相比，这有什么优势:
fn next(&mut self) -> Option<u32> {
let tmp = self.next;
self.next = self.curr + self.next;
self.curr = tmp;
Some(self.curr)
}