how to convert mpz_t to a char variable

[Ivan Döbeli]

Hello,

how can i convert a mpz_t 16base variable to a char variable to create 
the sha256 checksum of it (i wan't to use 
https://create.stephan-brumme.com/hash-library/).

thanks in advance for your support.

best regards,
Ivan

#include <gmp.h>
#include <stdio.h>
#include <assert.h>
#include <iostream>
#include <string>
using namespace std;
int main(){
   mpz_t n;
   int flag;
   mpz_init(n);
   mpz_set_ui(n,0);
   flag = 
mpz_set_str(n,"14f8da6389f9c2dd692ddc10aec26db4498f6a787682dd63af59f73e86399923", 
16);
   unsigned long i;
//  for(i=0; i<18446744073709551615UL; i++) {
   for(i=0; i<4096; i++) {
     gmp_printf("%Zd\n", n);
     mpz_add_ui(n,n,1U);
   }
   mpz_clear(n);
}