[Ns-developers] using TypeId for Header/Trailer (and helpers)

[Mathieu Lacage]

hi,

I have just pushed code in http://code.nsnam.org/mathieu/ns-3-param
which makes the Header and Trailer classes use a TypeId to replace the
previously-used adhoc uid. There is no change in functionality but the
result is a net drop in number of lines of code in the packet metadata
implementation which I think is a great thing. The other rationale for
this change is to help gustavo's python bindings to allow them to get
more information about a packet's headers and trailers and to allow
python-based headers and trailers.

To get there, I had to split the TypeId functionality from the
src/core/object.h header to src/core/type-id.h and I added TypeId powers
to src/core/object-base.h. Another very nice side-effect of this change
is that the header src/core/object.h has become readable again, as well
as its implementation src/core/object.cc

Finaly, the last nice thing about this refactoring is that, if we want
to, we can re-use the ObjectBase (src/core/object-base.h) as a base
class for all the classes in src/helper/*. ObjectBase merely provides
TypeId/Attribute powers to its subclasses without requesting these
subclasses to support reference counting and/or object aggregation.

I was originally planning to make this change post-release but the code
turned out to be pretty clean reasonably quickly and helped me to fix a
bunch of bugs here and there in the wifi, and packet code.

So, I would like to merge this branch back into ns-3-dev as soon as
possible because I see little downsides to do so and many upsides. Are
there any comments about this ?

Mathieu