String/Char* Problem in GMP

I am using the GMP multiple precison package.

I need to input very large integers as strings, for example

Code:

---

mpz_init_set_str(x,"1234567890",10)

---

will set x to that large integer in quotes (10 gives the base.)

I want to be able to have the user enter the value, so I did something like:

Code:

---

#include <string>
#include <gmpxx.h> // GMP

string num;
std::cin >> num;
mpz_init_set_str(x,num,10)

---

but this causes g++ to give the following error:
error: cannot convert `std::string' to `const char*' for argument `2' to `int __gmpz_init_set_str(__mpz_struct*, const char*, int)'

Any ideas how to input a data type that will work?

I am using Ubuntu on an AMD64.

Thanks!

You need to use the c_str() member function, e.g. num.c_str()

nevermind i seriously need to start paying attention
when i know im half asleep

Quickest problem solution ever.

Thanks!

Laser light

Could you please elaborate on the use of c_srt() function?