Function to_fullwidth

pub fn to_fullwidth(ch: char) -> Option<char>

Returns the full-width form for ch. If no full-width form for ch exists, or ch is already in full-width form, returns None.

Example

assert_eq!(unicode_hfwidth::to_fullwidth('a'), Some('ａ'));
assert_eq!(unicode_hfwidth::to_fullwidth('カ'), None);