Function rust_sodium_sys::crypto_secretbox_xsalsa20poly1305

pub unsafe extern fn crypto_secretbox_xsalsa20poly1305(c: *mut u8,
                                                       m: *const u8,
                                                       mlen: c_ulonglong,
                                                       n: *const u8,
                                                       k: *const u8)
                                                       -> c_int