pub unsafe extern "C" fn gdk_pixbuf_savev_utf8(
    pixbuf: *mut GdkPixbuf,
    filename: *const c_char,
    type_: *const c_char,
    option_keys: *mut *mut c_char,
    option_values: *mut *mut c_char,
    error: *mut *mut GError
) -> gboolean
This is supported on Windows only.