Default constructor

From: al (allin_at_168.net)
Date: 12/30/03 

Date: Tue, 30 Dec 2003 18:53:01 GMT

class Base
{
  public:
     //Base() {}
     Base(int m) {}

};

class Derive : public Base
{
  public:
     Derive(int m) {}

};

The above code keeps giving compiler error: 'Base': no appropriate default
constructor available, until a default cstor, Base() is added into Base
class.

Does this mean that a default cstor has always to be added whenever a
non-default cstor present?

Or is this default cstor, Base(), only required during inheritance? How to
make Derive to call Base(int m) rather than Base()?

In general, when does a default cstor have to be provided?

Thanks!