[fpc-devel] C++ Linking technology

[Michael Van Canneyt]

On Fri, 27 Apr 2007, ik wrote:

> On 4/27/07, Daniël Mantione <daniel.mantione at freepascal.org> wrote:
> >
> >>
> >> Op Fri, 27 Apr 2007, schreef Felipe Monteiro de Carvalho:
> >>
> >> > Hallo,
> >> >
> >> > Another day Florian was talking about the cppclass, a experimental
> >> > feature to link to c++
> >> >
> >> > I would like to know: Could someone inherit a class based on cppclass
> >> > with only external functions and then add to it it´s own methods and
> >> > fields?
> >> >
> >> > If this doesn´t exist yet, I would say it would be a good adition,
> >> > because then one can use the c++ classes like they are often used on
> >> > c++ app: By inheriting them and adding your own code.
> >> >
> >> > This is a very specific question, so I could just ask Florian
> >> > directly, but I guess that here everyone will have access to the
> >> > answer =)
> >>
> >> To be able to support such a thing you would have to implement all
> >> features of C++ objects into Pascal, effectively turning Pascal into C++
> >> with a different syntax. The proper way would be to have the C++ class
> >> implement a Pascal interface, so it can interoperate with Pascal code.
> >>
> >
> >How does other languages such as Perl/Ruby/Python (for example) etc,
> >handle such connections ?

They don't have to: the compilers/interpreters for these languages are 
written in C. All they need to do in the worst case is compile a small 
stub. For Pascal, the situation is not so simple, as there is no connection
with C whatsoever.

Michael