Function Overloading

[cyberdude]

hi all
While learning function overloading i came across the following example to illustrate a correct and incorrect function overloading technique

float square(float f)
double square (float x);      // error 

corrected code is

float square(float f)  // different signature??? how come     
double square (double d);      // allowed???? 

please help me understand this.What is the logical explanation behind this.Why does compiler does not allow this....
thanks for your time,
cyber dude

[jlb]

The first snippet is not allowed because to overload a function the parameters must be different. Just changing the return type is not enough.

[MiiNiPaa]

function signature consist from it name and number and types of arguments

void example(int x, int y = 0); //signature is example(int, int)
int example(int x, int y); //signature is example(int, int) : same as previous, not allowed 

void example(int x, int y = 0); //signature is example(int, int)
int example(int x); //signature is example(int) : not same as previous, allowed
//[...]
example(1);//however this will be ambiguous 

[Daleth]

You can think of the examples this way: when you call the function and pass in a parameter of a specific type, how will the program know which function to call? The program must differentiate among functions with the same name based on which parameters each accepts.