Function wcstok 

#[unsafe(no_mangle)]
pub unsafe extern "C" fn wcstok(
    wcs: *mut wchar_t,
    delim: *const wchar_t,
    state: *mut *mut wchar_t,
) -> *mut wchar_t

See https://pubs.opengroup.org/onlinepubs/9799919799/functions/wcstok.html.