#ifdef __cplusplus // Are we compiling this with a C++ compiler ?
extern "C" {
    class Foo;
    typedef Foo FOO;
#else
    // From the C side, we use an opaque pointer.
    typedef struct FOO FOO;
#endif

// Constructor
FOO* create_foo(int a, int b);

// Destructor
void delete_foo(FOO* foo);

// The const qualificators maps from the member function to pointers to the
// class instances.
int foo_bar(const FOO* foo, int c);
double foo_baz(const FOO* foo, double d);

void foo_speaker(const char* s);

#ifdef __cplusplus
}
#endif