test.cpp

#include <iostream>

bool false_val;
bool other_false_val = bool();

int main()
{
   bool true_val();
   bool val;

   bool *ptr();
   bool *null_ptr(0);   
   bool *other_ptr;

   std::cout << "Global initialization (bool): " << false_val << '\n'
             << "Other global initialization (bool): " << other_false_val << '\n'
             << "Default initialization (bool): " << true_val << '\n'
             << "Uninitialized (bool): " << val << '\n'
             << "Default initialization (pointer): " << ptr << '\n'
             << "Is it null? " << (nullptr == ptr) << '\n'
             << "Default initialization (pointer): " << null_ptr << '\n'
             << "Is it null? " << (nullptr == null_ptr) << '\n'
             << "Uninitialized (pointer): " << other_ptr << '\n'
             << "Is it null? " << (nullptr == other_ptr) << '\n';
}