Related Blog Items

• C++ Advanced Tutorial - Lesson 10
• Implicit Type Conversions - part 2

A multiply inherited class object can be converted into a second base class.

For ex:

struct A{  int i;  virtual ~A () {}};

struct B {  bool b; };

struct D: public A, public B{  int k;  D() { b = true; i = k = 0; }};

A *ptra = new D;B *ptrb = dynamic_cast< B* >ptra;

The static type for ptra is A * where as the dynamic type is D *. Normal static cast can’t be used here as A and B are two different structures. reinterpret_cast<> will result in simply assigning ptra to ptrb. But the address of B subobject and A subobject in D are different. So to do so we have to calculate the address of B at runtime which can be achieved by dynamic_cast<>

[tags]type casting, cross casting, type casts, c++ type casting, dynamic_cast<>, static_cast<>[/tags]

Popularity: 4%

You need to log on to convert this article into PDF

Related Blog Items

• C++ Advanced Tutorial - Lesson 10
• Implicit Type Conversions - part 2

This entry was written by ponnada and posted on December 21, 2006 at 7:47 pm and filed under Type Casting. Bookmark the permalink. Follow any comments here with the RSS feed for this post. Post a comment or leave a trackback: Trackback URL.