Hey,
does anybody know a standard or some rules for desiging a c interface for c++
classes? I.e. naming constrains, sequence of parameters (in, inout, in),
posisiton of the additional parameter which represents the object of the
method, etc.
There are some hints in a documentation of sun for wrappers, but it is only a
first small step, I think.
Thanks
Frank Rupprecht
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>>>>> On 24 Jan 92 09:50:53 GMT, frank@cadlab.de (Frank Rupprecht) said:

> does anybody know a standard or some rules for desiging a c interface for
> c++ classes? I.e. naming constrains, sequence of parameters (in, inout, in),
> posisiton of the additional parameter which represents the object of the
> method, etc.

The only safe approach I've seen is to develop C-style functions that call the
appropriate member functions on your objects:

class A { /*member info*/ };

extern "C" func(/*parmlist*/)
{
 A a;  /* either locally or globally declared */
 a.memberfunc();
 ...
}

Your C using clients would call these "envelope" functions in order to work
with the pure C++ routines.  I've yet to do this, though, so I'm not sure of
all the "gotchas".  One well-known "gotcha", though, is initialization of
global objects that your "C++" library (I assume all the func()'s are in a
library) might be using.  Presumably, your C users have written and compiled
most of their code (including the main routine) using C and a C compiler.
There is usually some sort of "magic" that C++ compilers perform to ensure
that the global information is set up before the main routine starts.  You'll
have to determine how much of a problem this is for you.
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