I can create multi precision integers from a string with standard base
#include <boost/multiprecision/gmp.hpp>
...
using namespace boost::multiprecision;
mpz_int decimal("10");
mpz_int hexadecimal("0xa");
mpz_int octal("012");
mpz_int binary("0b1010");
to use base 2 to 62 like in GMP, one can use for example
#include <gmp.h>
...
mpz_t auxiliary;
mpz_init(auxiliary);
mpz_set_str(auxiliary,"11",9);
mpz_int j = auxiliary;
mpz_clear(auxiliary);
Is there a more direct approach with no auxiliary variable ?