I want to do a function that uses pointers a s parameters and return one of the pointers, is it possible?
Example:
int* sum(int* x, int* y, int* total){
total=x+y;
return total;
}
I get this error:
main.cpp:10:13: error: invalid operands of types 'int*' and 'int*' to binary 'operator+'
How can I do that using only pointers and not references?
You need to dereference the pointers to return a reference to the object they point to:
*total = *x + *y;
However, in C++ you can use references to facilitate this:
int sum(int x, int y, int& total)
{
total = x + y;
return total;
}
The reference is only declared with total because that is the only argument we need to change. Here's an example of how you would go about calling it:
int a = 5, b = 5;
int total;
sum(a, b, total);
Now that I think of it, since we're using references to change the value, there really isn't a need to return. Just take out the return statement and change the return type to void:
void sum(int x, int y, int& total)
{
total = x + y;
}
Or you can go the other way around and return the addition without using references:
int sum(int x, int y)
{
return x + y;
}
Assuming this worked (it doesn't compile, rightly so):
total=x+y;
it would give you the pointer that points at the address of x + the address of y. Since this is [nearly] always nonsense, the compiler doesn't allow you to add two pointers together.
What you really want is to add the value that int *x and int *y POINTS AT, and store it in the place that total points at:
*total = *x + *y;
*total = *x + *y(and as a side note, both the x and y pointers should be const, or in-fact not even pointers in this example).