Constructing and Destroying TXBase

TXBase provides two public constructors:

TXBase(const string& msg);
TXBase(const TXBase& src);

The first constructor initializes the classlib.hlpxmsg" base class with the value of the string parameter, calling the xmsg constructor that takes a string parameter. The second creates a new object that is a copy of the TXBase object passed in as a parameter.

Both constructors increment the TXBase data member TXBase::InstanceCount, a static int (causing there to be only a single instance of the member no matter how many actual TXBase or TXBase-derived objects exist in the application). The TXBase destructor decrements InstanceCount. The destructor is declared virtual to allow easy overriding of the destructor.

Because each new TXBase or TXBase-derived object increments InstanceCount, and each deleted TXBase or TXBase-derived object decrements InstanceCount, the value of InstanceCount reflects the total number of TXBase and TXBase-derived objects existing in the application at the time. To access InstanceCount from outside a TXBase or TXBase-derived class, qualify the name InstanceCount with a TXBase:: scope qualifier.