How do I manage an array of mpz_t

Question

I'm using GMP and I need an array of mpz_t. sizeof(mpz_t) gives 16, but the numbers I'm storing are considerably larger than that. Does mpz_t grow "in place", i. e. do I need to allocate more memory and allow for growth in-place, or does GMP allocate the space for them elsewhere and just keep references (in which case, I'm assuming, I won't have to take any special precautions.)

Answer 1

It is safe to declare an array to store a number of mpz_t values. According to the GNU MP manual:

mpz_t is actually implemented as a one-element array of a certain structure type. This is why using it to declare a variable gives an object with the fields GMP needs, but then using it as a parameter passes a pointer to the object. Note that the actual contents of an mpz_t are for internal use only and you should not access them directly if you want your code to be compatible with future GMP releases.