C++ set precision and printf example

gistfile1.txt

#include <iostream>
#include <cstdio>
#include <iomanip>
#include <float.h>

using namespace std;

int main()
{
	printf("%.*f\n", FLT_DIG, 3.141592653589);
	cout << std::setprecision(FLT_DIG + 10) << 3.141592653589 << endl;
}