Function FT_IS_SFNT 

pub unsafe fn FT_IS_SFNT(face: FT_Face) -> bool

Returns true whenever a face object contains a font whose format is based on the SFNT storage scheme.

This usually means: TrueType fonts, OpenType fonts, as well as SFNT-based embedded bitmap fonts.

Safety

face must be a valid FT_Face that can be dereferenced.