function overloading/ declare function

• Declare a function

To declare a function without identifying the argument list, you can do it in this way:

void say hello(...);

here, you use three point (...) to indicate that the function have no argument.

• function overloading

Keep in mind that the signature, not the function type, enables function overloading. For example, the following two declaration are incompatible:

long gronk (int n, float m);　　　#1　//same signature

double gronk(int n, float m);　　#2　//hence not allowed

why, for example, if this is possible:

int hel=0;

float haa=3;

gronk(hel, haa); //which function to use, #1 or #2, it is conflict.

therefore,  C++ doesn't allow you to overload gronk() in this fashion. You can have different return type, but only if the signature are also different, for example:

long gronk(int n, float m);

double gronk(double n, double m);　　//now it is allowed