Function split_at_char_index 

pub fn split_at_char_index(string: &str, index: usize) -> (&str, &str)

Examples

use persistent_rope::split_at_char_index;

assert_eq!(split_at_char_index("長さ", 1), ("長", "さ"));
assert_eq!(split_at_char_index("長さ", 0), ("", "長さ"));
assert_eq!(split_at_char_index("長さ", 2), ("長さ", ""));
assert_eq!(split_at_char_index("長さ", 3), ("長さ", ""));