Question

In C# you can use as to convert a type or get null:

Object o = Whatever();
String s = o as String;

Is there a similar easy way to achieve this in C++?

I’m using Visual Studio 2010, if that’s important.

[Update]: Remember, there is a very important difference between casting and using as. Casting (at least in C#) will throw an exception if the type does not match:

Object o = null;
String s = (String)o; // Will crash.

Answer 1

In C++, this would be a dynamic_cast, if you had a hierarchy where Object is the parent and String is the child.

Object * p = createMyObject();
String * s = dynamic_cast<String *>(p);
if(s)
{
  ...
}

Dynamic casting a pointer will return a pointer to the object if the cast is possible, or a null pointer if not.

Also, dynamic casting a reference will return a reference to the object if the cast is possible, or throw an exception.