1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
|
use inplace_vec_builder::InPlaceVecBuilder;
struct Collection {
elements: Vec<u32>,
}
impl Collection {
fn op(&mut self) {
let mut res = self
.elements
.iter()
.filter(|x| **x > 5)
.map(|x| *x * 2)
.chain(std::iter::once(123))
.collect();
std::mem::swap(&mut self.elements, &mut res);
}
fn inplace_op(&mut self) {
let mut t = InPlaceVecBuilder::from(&mut self.elements);
while let Some(elem) = t.pop_front() {
if elem > 5 {
t.push(elem * 2);
}
}
t.push(123);
}
}
fn main() {
let mut x = Collection {
elements: Vec::new(),
};
x.op();
x.inplace_op();
}
|
