mpf_class::get_str error

[Mark Stankus]

#include "gmpxx.h"

The following program gave me the output 1.5 on one line and 15 on the next.

// start main.,cpp
#include <iostream>

int main() {
  mpf_class f(1.5);
  std::cout << f << std::endl;
  long xx(1000L);
  std::cout << f.get_str(xx) << std::endl;
  return 0;
}
// end main.cpp

Other info:
1) I installed gmp using homebrew
2) Darwin Marks-iMac.local 15.5.0 Darwin Kernel Version 15.5.0: Tue
Apr 19 18:36:36 PDT 2016; root:xnu-3248.50.21~8/RELEASE_X86_64 x86_64
3) compiled with
    g++ -L /usr/local/Cellar/gmp/6.1.1/lib/ -l gmpxx -l gmp test.cpp

Mark S.