Macro str_join

macro_rules! str_join {
    ($sep:expr, $(&)? []) => { ... };
    ($sep:expr, $slice:expr $(,)*) => { ... };
}

Macro equivalent of <[&str]>::join, which takes constants as arguments.

This acts like a compile-time-evaluated version of this function:

pub const fn str_join(
    delimiter: impl StrOrChar,
    strings: &'static [&'static str],
) -> &'static str

Where impl StrOrChar is either a &'static str or char

Example

use konst::string::str_join;

{
    const COMMA: &str = ",";
    const S: &[&str] = &["these", "are", "words"];
    assert_eq!(str_join!(COMMA, S), "these,are,words");
}

assert_eq!(str_join!(",", &[]), "");

assert_eq!(str_join!(" ", &["foo", "bar", "baz"]), "foo bar baz");

// char separator
assert_eq!(str_join!(' ', &["foo", "bar", "baz"]), "foo bar baz");