This is the output when compiled with VC2005

During compilation:
warning C4351: new behavior: elements of array 'Init::ai' will be default
initialized
warning C4351: new behavior: elements of array 'Init::bi' will be default
initialized

When running

UnInit:
ai = {-858993460, -858993460, -858993460, -858993460, }
bi = {204, 204, 204, 204, }

Init:
ai = {0, 0, 0, 0, }
bi = {0, 0, 0, 0, }

Funny enough the following change works as expected:

struct Init_POD
{
   int ai[Size];
   bool bi[Size];
};

class Init {
   Init_POD pods;
public:
   Init() : pods() { }
   friend std::ostream& operator<<(std::ostream& o, const Init& i);
};

std::ostream&
operator<<(std::ostream& o, const Init& in)
{
   o << "Init:\n";
   o << "ai = {";
   std::copy(in.pods.ai, in.pods.ai + Size, std::ostream_iterator<int>(o,
", "));
   o << "\b\b}\n";

   o << "bi = {";
   std::copy(in.pods.bi, in.pods.bi + Size, std::ostream_iterator<bool>(o,
", "));
   o << "\b\b}";

   return o;
}

Regards,
Patrick