title: GNU GMP mpz_powm() without mod
body: <p><a href="http://gmplib.org/manual/Integer-Exponentiation.html#Integer-Exponentiation" rel="nofollow">GNU GMP</a> provides a functions called <code>mpz_powm(rop, base, exp, mod)</code> which allows me to power a very big integer value by another very big integer value. The function also forces me to modulate the result by the 4th parameter. That's what the "m" stands for in <code>mpz_powm</code>. The reason why there isn't a function without a mod parameter could be to avoid very big results which may fill up your whole memory like: <code>2^(2^64)</code>. I'd like to know if there is a possibility anyway to use that function without specifying a mod parameter by just taking the risk to reach your memory limit.</p>