The predicate for dual-width fonts. This function is deprecated.
font-dual-width-p port &optional font => result
port
A graphics port.
font
A font object.
result
A boolean.
The function font-dual-width-p returns t when the font is fixed-width and contains double width characters. Such a font is dual-width.
font-dual-width-p
t
font-fixed-width-p
CAPI User Guide and Reference Manual (Windows version) - 3 Aug 2017