Set/Unset showpos format flag
  showpos sets the format flag to always insert a plus sign (+) before every non-negative value.
  noshowpos unsets this flag, not showing any sign before non-negative values.

Parameters.

str

Stream object where to apply. This is a manipulator parameter.

Return Value.
  A reference to the stream object.

Example.

// modify showpos flag
#include <iostream>
using namespace std;

int main () {
  int n;
  n=75;
  cout << showpos << n << endl;
  cout << noshowpos << n << endl;
  return 0;
}

See also.
  flags, setf, unsetf
  ios_base class