实现重载函数 Double(x)，返回值为输入参数的两倍；参

解：

源程序：

#include <iostream.h>
int Double(int);
long Double(long);
float Double(float);
double 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: " << myInt << "\n";
cout << "myLong: " << myLong << "\n";
cout << "myFloat: " << myFloat << "\n";
cout << "myDouble: " << myDouble << "\n";
doubledInt = Double(myInt);
doubledLong = Double(myLong);
doubledFloat = Double(myFloat);
doubledDouble = Double(myDouble);
cout << "doubledInt: " << doubledInt << "\n";
cout << "doubledLong: " << doubledLong << "\n";
cout << "doubledFloat: " << doubledFloat << "\n";
cout << "doubledDouble: " << doubledDouble << "\n";
return 0;
}
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;
}