Compiling error... a function-definition is not allowed here before â{â token

I keep getting this compiling error

a function-definition is not allowed here before â{â token

Code:

#include <iostream>
#include <cstdlib>

using namespace std;

double areaOfCircle (int r);
double lbsToKgs (int lbs);
double mphToFps (int mph);
int coinFlip (void);
int rollDi (void);

int main(void)
{
   int done = 0;
  char choice;
   while ( !done )
   {
      cout << "Menu"
              "[1] Area of Circle"
              "[2] Convert lbs to kgs"
              "[3] Convert mph to fps"
              "[4] Coin flip"
              "[5] Roll dice"
              "Enter choice (q to quit)? ";
      cin >> choice;
      switch(choice)
      {
            case '1':
            {
               int r;
               cout << "Enter positive int radius? ";
               cin >> r;
               double areaOfCircle (int r)
               {
                  double pi = 3.14159;
                  double a;
                  a = pi * r * r;
               return a;
               }
               cout << areaOfCircle(r) << "units squared" << endl;
            break;
         }
         case '2':
         {
            int lbs;
            cout<<"Enter positive int lbs? ";
            cin>>lbs;
            double lbsToKgs (int lbs)
            {
               double b;
               b = lbs * 0 .45359237;
            return b;
            }
            cout << lbsToKgs(lbs) << "kgs" << endl;

            break;
         }
         case '3':
         {
            int mph;
            cout << "Enter pos int mph? ";
            cin >> mph;
            double mphToFps (int mph)
            {
               double c;
               c = mph * 1.46666667;
            return c;
            }
             cout << mphToFps (mph) << "fps" << endl;
            break;      
         }
      case '4':      
         {
            int coinFlip (void)
            {
               int f;
               f = lrand48() % 2;
               if (f ==1)
               {
                  cout << "Heads" <<endl;
               }
               else
               {
                  cout << "Tails" <<endl;
               }
               return f;
                }
            break;
         }
      case '5': 
         {         
            int rollDi (void)
            {
               int s, t;
               s = (lrand48() % 6) + 1;
               t = (lrand48() % 6) + 1;
               if(s==1 && t==1)
               {
                  cout << "Snake eyes!" << endl;
               }
               else
               {
                  cout << s << " " << t << endl;
               }
               return s,t;
            }
         break;
      }
      case 'q':
      {
         done = 1;
         break;
      }
      default:
         cout<< "Invalid Choice try again";
      }
   }
   return 0;
}

This is the output:
p7.cc: In function âint main()â:
p7.cc:39: error: a function-definition is not allowed here before â{â token
p7.cc:54: error: a function-definition is not allowed here before â{â token
p7.cc:69: error: a function-definition is not allowed here before â{â token
p7.cc:80: error: a function-definition is not allowed here before â{â token
p7.cc:124: error: expected `}' at end of input
p7.cc:124: error: expected `}' at end of input
p7.cc:124: error: expected `}' at end of input
p7.cc:124: error: expected `}' at end of input


I am really confused why these errors are there. Any help would be great.

The compiler is being as explicit as possible: you're defining a function where it is not allowed to define a function! Here is a snippet

Code:

int main(void)
{
   int done = 0;
  char choice;
   while ( !done )
   {
      cout << "Menu"
              "[1] Area of Circle"
              "[2] Convert lbs to kgs"
              "[3] Convert mph to fps"
              "[4] Coin flip"
              "[5] Roll dice"
              "Enter choice (q to quit)? ";
      cin >> choice;
      switch(choice)
      {
            case '1':
            {
               int r;
               cout << "Enter positive int radius? ";
               cin >> r;
               double areaOfCircle (int r)
               {
                  double pi = 3.14159;
                  double a;
                  a = pi * r * r;
               return a;
               }
               cout << areaOfCircle(r) << "units squared" << endl;
            break;
         }
//.. rest of 'main' here
}

You're defining this function inside of the function "main". Move the definition outside of this function, and simply call the function from "main". So it may look like:

Code:

 double areaOfCircle (int r)
               {
                  double pi = 3.14159;
                  double a;
                  a = pi * r * r;
               return a;
               }

int main(void)
{
   int done = 0;
  char choice;
   while ( !done )
   {
      cout << "Menu"
              "[1] Area of Circle"
              "[2] Convert lbs to kgs"
              "[3] Convert mph to fps"
              "[4] Coin flip"
              "[5] Roll dice"
              "Enter choice (q to quit)? ";
      cin >> choice;
      switch(choice)
      {
            case '1':
            {
               int r;
               cout << "Enter positive int radius? ";
               cin >> r;
               cout << areaOfCircle(r) << "units squared" << endl;
            break;
         }
//.. rest of 'main' here
}

thanks! got it