Unicode-aware algorithm to pad or truncate str in terms of displayed width.

Safely truncate string to display width even not at character boundaries.

use unicode_truncate::UnicodeTruncateStr;

fn main() {
    assert_eq!("你好吗".unicode_truncate(5), ("你好", 4));
}

Making sure the string is displayed in exactly number of columns by combining padding and truncating.

use unicode_truncate::UnicodeTruncateStr;
use unicode_truncate::Alignment;
use unicode_width::UnicodeWidthStr;

fn main() {
    let str = "你好吗".unicode_pad(5, Alignment::Left, true);
    assert_eq!(str, "你好 ");
    assert_eq!(str.width(), 5);
}

unicode-truncate can be built without std by disabling the default feature std. However, in that case unicode_truncate::UnicodeTruncateStr::unicode_pad won't be available because it depends on std::string::String and std::borrow::Cow.