1use alloc::collections::VecDeque;
2#[cfg(feature = "std")]
3use std::io;
4
5use super::Buf;
6
7impl Buf for VecDeque<u8> {
8 fn remaining(&self) -> usize {
9 self.len()
10 }
11
12 fn chunk(&self) -> &[u8] {
13 let (s1, s2) = self.as_slices();
14 if s1.is_empty() {
15 s2
16 } else {
17 s1
18 }
19 }
20
21 #[cfg(feature = "std")]
22 fn chunks_vectored<'a>(&'a self, dst: &mut [io::IoSlice<'a>]) -> usize {
23 if self.is_empty() || dst.is_empty() {
24 return 0;
25 }
26
27 let (s1, s2) = self.as_slices();
28 dst[0] = io::IoSlice::new(s1);
29 if s2.is_empty() || dst.len() == 1 {
30 return 1;
31 }
32
33 dst[1] = io::IoSlice::new(s2);
34 2
35 }
36
37 fn advance(&mut self, cnt: usize) {
38 self.drain(..cnt);
39 }
40}
41