ct_visual_char
used = ct_visual_char(dst, buffsize - (dst - buff), *s);
protected ssize_t ct_visual_char(wchar_t *, size_t, wchar_t);
used = ct_visual_char(el->el_keymacro.buf + cnt,
used = ct_visual_char(el->el_keymacro.buf + cnt, KEY_BUFSIZ - cnt,
ssize_t l = ct_visual_char(dbuf, VISUAL_WIDTH_MAX, *p);
ct_visual_char(visbuf, VISUAL_WIDTH_MAX, c);
ct_visual_char(visbuf, VISUAL_WIDTH_MAX, c);
ssize_t vcnt = ct_visual_char(visbuf, VISUAL_WIDTH_MAX, c);