harfbuzz_sys::hb_font_get_glyph_extents_func_t

type hb_font_get_glyph_extents_func_t = Option<extern fn(font: *mut hb_font_t, font_data: *mut c_void, glyph: hb_codepoint_t, extents: *mut hb_glyph_extents_t, user_data: *mut c_void) -> hb_bool_t>;