How to use c++ objects in c?

Question

I have 2 projects decoder and dec in my visual studio. One has C code and other has C++ code using stl respectively.How do I instantiate the c++ classes in my c code inside

Answer 1

you would need to write a wrapper in C.

something like this:

in class.h:

struct A{
   void f();
}

in class.cpp:

void A::f(){
}

the wrapper.cpp:

#include "wrapper.h"
void fWrapper(struct A *a){a->f();};
struct A *createA(){
   A *tmp=new A();
   return tmp;
}

void deleteA(struct A *a){
 delete a;
}

the wrapper.h for C:

struct A;
void fWrapper(struct A *a);
A *createA();

the C program:

#include "wrapper.h"
int main(){
    A *a;
    a=createA();
    fWrapper(a);
    deleteA(a);
}