Addresses of array elements as template non-type paramater

[Quentin]

Hi there!

I can't understand why addresses of array elements cannot appear as non-type parameter in class template. I know that something like this:

int array[3] = {45, 57, 24};
//...
template <int *p>
class X { };

void fun()
{
X<&array[1]> xxx;
}

is dereferencing (in line 8), beacuse:

&array[1] = &(*(array+1))

But I don't know why compiler can't accept this expression:

X<array + 1> xxx;

Thank you.

[Bazzy]

Template values should be constants known at compile time

[Quentin]

So... How do you explain something like this:

extern Foo foo;
//...
template <Foo* pointer>
class X { };
//...
X<&foo> x;

Compiler doesn't know foo's address yet :-/...