Question

So I just learned via a compiler error that in-class initialization of arrays is invalid (why?). Now I would like to have some arrays initialized in a template class, and unfortunatly the contents depend on the template parameter. A condensed testcase looks like this:

template<typename T>
struct A {
    T x;
    static const int len = sizeof(T);         // this is of course fine
    static const int table[4] = { 0, len, 2*len, 3*len };    //this not
}

Any idea how to pull out the constant array?

EDIT: Added the ‘int’s.

Answer 1

Just as you’d do it without templates; put the initialization outside the class’ declaration:

template<class T>
const int A<T>::table[4] = { 0, len, 2*len, 3*len };