using an absolute pointer address as a template argument

Question

I have a template class which takes as its first template argument a foo * pointer. I\'d like to instantiate one of these with a foo located at an absolute address, like so:

Answer 1

Facing the same problem (on an STM32), as a work-around I found function pointer template parameters, like so:

template
class LedToggle
{
    public:

    void Update()
    {
        // ...
        PORT()->BSRR = mSetReset & mask;
        // ...
    }
};

constexpr GPIO_TypeDef* Port_C() {
  return PORTC;
}

LedToggle led;

Notice that we use a function pointer as template parameter, to a function that returns the desired actual pointer. Inside that function casts are allowed; and since the function is declared constexpr the compiler may (should) optimize away the actual function call and use the function's return value like a literal.