Question

I am using MPIR 2.4.0 on Windows (MSVC 2010) and I was trying to add an unsigned 64bit integer to a mpz_t number. However it seems that MPIR/GMP does not support direct conversion between 64bit Integers and mpz_t. Does this mean I have to convert my uint64 to a string and read this via mpz_init_set_str?
Neither is this very appealing nor does it look very quick – two conversion for nothing.

Did I miss something or what is the trick/hack to use here?

Cheers,

Philipp

Answer 1

As suggested by Banthar use mpz_import, but I’d suggest the following which does not rely on the platform endianness:

mpz_import(b, 1, 1, sizeof(a), 0, 0, &a);