stdx/
iter.rs

1#[cfg(feature = "alloc")]
2use core::fmt;
3
4#[cfg(feature = "alloc")]
5use alloc::string::String;
6
7pub trait IteratorExt: Iterator {
8    #[cfg_attr(docsrs, doc(cfg(feature = "alloc")))]
9    #[cfg(feature = "alloc")]
10    fn join_(&mut self, sep: &str) -> String
11    where
12        Self::Item: fmt::Display,
13    {
14        use core::fmt::Write as _;
15
16        match self.next() {
17            None => String::new(),
18            Some(first) => {
19                let (lower, _) = self.size_hint();
20                let mut buf = String::with_capacity(sep.len() * lower);
21                write!(&mut buf, "{first}").unwrap();
22                self.for_each(|item| {
23                    buf.push_str(sep);
24                    write!(&mut buf, "{item}").unwrap();
25                });
26                buf
27            }
28        }
29    }
30}
31
32impl<I: Iterator> IteratorExt for I {}
stdx/iter.rs

stdx/
iter.rs
