Bison C++ parser

[Hans Aberg]

If you are interested in making a Bison C++ parser, here is what I think is
needed:

- An option
  %code <code_name> {
    ...
  }
that puts the stuff ... into a M4 macro with name derived from <code-name>.
This will be needed, because code can under C++ be put in several places,
where C only has a few.

- An option %typed, that checks Bison static types, without implementing a
semantic type union, as %union does.

With these features in hand, it will not be so difficult to write C++ parsers.

  Hans Aberg