sizeof in static const member initialization

Question

I have such code:

class A
{
public:

    unsigned long a;
    static const unsigned long b = sizeof(a); // \"error C2327: \'A::a\' : is not a type name, static,          


        

Answer 1

StoryTeller's answer specifies why this didn't work on visual-studio-2005. Namely because it wasn't supported until c++11.

As far as visual-studio-2013 it's not fully c++11 compliant. But I've validated that this code works around the deficiency:

static const unsigned long b = sizeof(decltype(a))

If you want something that will work with visual-studio-2005 as well, consider making b a global, instead of a static member of A:

const unsigned long b = sizeof(A().a)