Re: mixing C/C++

[elathan@phys.uoa.gr]

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Quoting Steven Shaw <steven_shaw@iprimus.com.au>: 
 
> On Tuesday 25 November 2003 03:55, Elias Athanasopoulos wrote: 
> > Apparently it is fine. The problem occures when I am wrapping 
> > a class which inherits from multiple classes with virtual 
> > functions. 
>  
> That should be fine too. 
>  
> > Any workarounds? 
>  
> Maybe you have C++ code with static members. If so you need to compile 
main() 
>  
> with a C++ compiler. Here is an excellent resource: 
>  
> 	http://www.parashift.com/c++-faq-lite/mixing-c-and-cpp.html 
 
This is what I read and came to the above conclusion. 
 
It states (32.9): 
 
You can safely access a C++ object's data from a C function if the C++ class:  
 
Has no virtual functions (including inherited virtual functions) 
  
So I guess that is a problem. I verified that with the attached source file. Compile 
the lib.cxx as a shared libfoo.so file and then try to call f->dump3() (f is struct 
*Foo).   
 
Also, I don't have main() in my project since it is a shared library. 
 
Thanks for your help. 
 
Regards, 
Elias 
 
  

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#include <stdlib.h>
#include <stdio.h>

class Taz {
public:
  Taz();
  ~Taz();

  virtual void dump3(void);
};

class Bar {
public:
  Bar();
  ~Bar();

  virtual void dump2(void);
};

class Foo : public Bar, public Taz{
public:
	Foo();
	~Foo();

	void dump(void);
};

Foo::Foo()
{
}

void Foo::dump(void)
{
	printf("Foo Hello!\n");
}

Bar::Bar()
{
}

Bar::~Bar()
{
}

void Bar::dump2(void)
{
	printf ("Bar Hello\n");
}

Taz::Taz()
{
}

void Taz::dump3(void)
{
	printf ("Taz Hello!\n");
}

extern "C"
Foo * wrap_foo_ctor()
{
	return new Foo();
}

extern "C"
void wrap_foo_dump(Foo *f)
{
	f->dump();
}

extern "C"
void wrap_bar_dump2(Bar *b)
{
	b->dump2();
}

extern "C"
void wrap_taz_dump3(Taz *t)
{
	t->dump3();
}