[Libssh] Enhancements proposals

[Alexander Lamaison]

> > Well I know that C is compatible with C++, but not C++ with C, unless
> by
> > using very complex technics. So I'm very curious how you would do
> your
> > stub in such a way that any native C library could compile and link
> > against it.
> Just compile with g++ a code like
> extern "C" {
>   struct my_c_struct {
>      myClass *c;
>   };
>   int C_function_do_this(struct my_c_struct *this, int arg){
>     return this->c->do_this(arg);
>   }
> }
> 
> it works, I've tested it.
> >
> > And even if it's possible, you'll still have to design your C API...
> that's right. It will follow the external C++ api. But it's much less
> hasle than having to design the whole code with these tricks.

The biggest problem with C++ libraries is that you can only link with code
that has been compiled with the *same C++ compiler*!  That often means the
same version of the compiler.  The reason for this is that, unlike for C,
there is no agreed standard ABI.

Therefore, C++ libraries are usually distributed in the form of template
libraries so that they are compiled directly into the client application
rather than linked to it.  Compiled C++ libraries are troublesome and rare
even in open source projects such as Linux distros.

Alex Lamaison