A guarded pointer, \fCTQGuardedPtr<X>\fR, behaves like a normal C++ pointer \fCX*\fR, except that it is automatically set to 0 when the referenced object is destroyed (unlike normal C++ pointers, which become "dangling pointers" in such cases). \fCX\fR must be a subclass of TQObject.
Guarded pointers are useful whenever you need to store a pointer to a TQObject that is owned by someone else and therefore might be destroyed while you still hold a reference to it. You can safely test the pointer for validity.
The functions and operators available with a TQGuardedPtr are the same as those available with a normal unguarded pointer, except the pointer arithmetic operators (++, --, -, and +), which are normally used only with arrays of objects. Use them like normal pointers and you will not need to read this class documentation.
For creating guarded pointers, you can construct or assign to them from an X* or from another guarded pointer of the same type. You can compare them with each other using operator==() and operator!=(), or test for 0 with isNull(). And you can dereference them using either the \fC*x\fR or the \fCx->member\fR notation.
A guarded pointer will automatically cast to an X*, so you can freely mix guarded and unguarded pointers. This means that if you have a TQGuardedPtr<TQWidget>, you can pass it to a function that requires a TQWidget*. For this reason, it is of little value to declare functions to take a TQGuardedPtr as a parameter; just use normal pointers. Use a TQGuardedPtr when you are storing a pointer over time.
Inequality operator; implements pointer semantics, the negation of operator==(). Returns TRUE if \fIp\fR and this guarded pointer are not pointing to the same object; otherwise returns FALSE.
Equality operator; implements traditional pointer semantics. Returns TRUE if both \fIp\fR and this guarded pointer are 0, or if both \fIp\fR and this pointer point to the same object; otherwise returns FALSE.
