fun_ptr.cpp

// in the calling function, pf = (*pf)
#include <iostream>
double betsy(int);
double pam(int);

// second argument is pointer to a type double function 
// that take a type int argument
void estimate(int lines, double(*pf)(int));

// in this method, we give the function name with 
// format: return type (*pf)(input type), and 
// pass method name to perfrom compute.

int main()
{
	using namespace std;
	int code;

	cout << "How many lines of code do you need? ";
	cin >> code;
	cout << "Here's Betsy's estimate: \n";
	estimate(code, betsy);
	cout << "Here's Pam's estimate: \n";
	estimate(code, pam);
	return 0;
}

double betsy(int lns)
{
	return 0.05 * lns;
}

double pam(int lns)
{
	return 0.03 * lns + 0.0004 * lns * lns;
}

void estimate(int lines, double (*pf)(int))
{
	using namespace std;
	cout << lines << " lines will take ";
	cout << (*pf)(lines) << " hour(s)\n";
}