On 24 Feb 2006, at 22:24, Akim Demaille wrote:
Le 23 févr. 06 à 21:34, Hans Aberg a écrit :
In summary, if one does not need a dynamic polymorphic variable
in the extra-parser computations, then a discriminating union
will be useful. But it does not serve as a replacement in the
case a dynamic polymorphic variable is needed.
There is no problem with storing a polymorphic pointer in a
variant.
The idea is to use the traditional C++ virtual hierarchy. This is
the model that was introduced into C++ as an extension of the
corresponding one in C.