8. Default constructor behavior of C++ types

More examples of the useful trick that we described:

int x = int();       // x == 0

double d = double(); // d == 0.0

bool b = bool();     // b == false

char* cp = char*();  // is a syntax error

However,

#include <iostream>

using namespace std;

template< typename ValueT >
class Thing {
public:
    Thing< ValueT >()
    {
        ValueT dummy = ValueT();
        // dummy is zero if ValueT is a pointer:
        std::cout << static_cast< void* >( dummy );
    }
};//class Thing

int main()
{
    Thing< char* > thing;
    return 0;
}