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Polyamorphic functions and compiler errors

syntax error (4)
Book I'm working from had me input a polymorphic function code. Got it in word for word, but I'm getting compiler errors. I'm not sure what's causing the errors, b/c I copied it verbatim. Thinking it may be a compiler issue...?

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In function 'long intDoulbe(long int)':
new declaration 'long int Doulbe(long int)'
ambiguates old declaration 'int Double(long it)'


So, that's the error. I get it for the functions float Double(float), long Double(long) and double Double(double). I know, horrible naming, but I'm copying out of the book...

Here's the code...

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#include <iostream>
using namespace std;

int Double(int);
int Double(long);
int Double(float);
int Double(double);

int main()
{
    int            myInt = 6500;
    long           myLong = 65000;
    float          myFloat = 6.5F;
    double         myDouble = 6.5e20;
    
    int            doubledInt;
    long           doubledLong;
    float          doubledFloat;
    double         doubledDouble;;
    
    cout << "myInt:\t " << myInt << endl;
    cout << "myLong:\t " << myLong << endl;
    cout << "myFloat:\t " << myFloat << endl;
    cout << "myDouble:\t " << myDouble << endl;
    
    doubledInt = Double(myInt);
    doubledLong = Double(myLong);
    doubledFloat = Double(myFloat);
    doubledDouble = Double(myDouble);
    
    cout << "doubledInt:\t " << doubledInt << endl;
    cout << "doubledLong:\t " << doubledLong << endl;
    cout << "doubledFloat:\t " << doubledFloat << endl;
    cout << "doubledDouble:\t " << doubledDouble << endl;
    
    system("pause");
}

int Double(int original)
{
    cout << "In Double(int)\n";
    return 2 * original;
}

long Double(long original)
{
     cout << "In Double(long)\n";
     return 2 * original;
}
     
float Double(float original)
{
      cout << "In Double(float)\n";
      return 2 * original;
      }
      
double Double(double original)
{
       cout << "In Double(double)\n";
       return 2 * original;
       }


The compiler I'm using is Dev C++ v4.9.9.2

I may be trying out Visual shortly, if you can think of any pros to that compiler vs. Dev, I'd like to know. Thanks!
MiiNiPaa (8886)
declarations vs definitions, find the difference:
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int Double(int);
int Double(long);
int Double(float);
int Double(double);
 
int Double(int);
long Double(long);
float Double(float);
idouble nt Double(double);

The compiler I'm using is Dev C++ v4.9.9.2
Stop using it right now. Like, select directory with it and press shift+delete.

It is terribly outdated, contains numerous bugs and does not eve support C++11 standard. If you want to continue using it, switch to Orwell Dev-C++ 5.6.3.
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