How to create an int pointer on the stack?

void func(int* pa开发者_如何学Goram){};
func(&123); //error: '&' on constant
funct(&int(123)) //error

That's not how pointers work.

You must first allocate memory for your 123, like this:

int x = 123;
func(&x);

You can't take the address of a temporary. Address-of operator (&) requires an lvalue as an argument.

void func(int* param){};
int main(){
  int k = 123;
  func(&k); //fine now
}

Declare an int variable, and then point to it:

int main() {
  int x = 123;
  func(&x);
}

If you want to declare a pointer on the stack, then declare an int-pointer variable:

int* p = &x;
func(p);

The keyword & must and should only be applied to actual variables, not operands.

The problem is that you're trying to take the address of an rvalue. Make it an lvalue:

n = 123;
func(&n);

void func(int* param)
{
    std::cout << * param << std::endl;
}

int main(int argc, char** argv)
{
    int a = 123;
    func(&a);

    return 0;
}