What is the VTable Layout and VTable Pointer Location in C++ Objects in GCC 3.x and 4.x?

I am looking for details of the VTable structure, order and contents, and the location of the vtable pointers within objects.

Ideally, this will cover single inheritance, multiple inheritance, and virtual inheritance.

References to external documentation would also be appreciated

Documentation of GCC 4.0x class layout is here and the Itanium, and more broadly GNU, ABI layout documents are here.

From stackoverflow grrussel

• This is probably described in C++ ABI.

  E.g., C++ VTable examples.

  From squadette