Call C++ from C

[flashdog]

Hello,
how can I call this C++ Code from C? I must use C, because Ruby-ffi
understand only C.

class Shape {
public:
  Shape() {
    nshapes++;
  }
  virtual ~Shape() {
    nshapes--;
  };
  double  x, y;
  void    move(double dx, double dy);
  virtual double area(void) = 0;
  virtual double perimeter(void) = 0;
  static  int nshapes;
};

class Circle : public Shape {
private:
  double radius;
public:
  Circle(double r) : radius(r) { };
  virtual double area(void);
  virtual double perimeter(void);
};

class Square : public Shape {
private:
  double width;
public:
  Square(double w) : width(w) { };
  virtual double area(void);
  virtual double perimeter(void);
};

#include "example.h"
#define M_PI 3.14159265358979323846

/* Move the shape to a new location */
void Shape::move(double dx, double dy) {
  x += dx;
  y += dy;
}

int Shape::nshapes = 0;

double Circle::area(void) {
  return M_PI*radius*radius;
}

double Circle::perimeter(void) {
  return 2*M_PI*radius;
}

double Square::area(void) {
  return width*width;
}

double Square::perimeter(void) {
  return 4*width;
}

Best regards

 

[Ian Collins]

Hello,
how can I call this C++ Code from C? I must use C, because Ruby-ffi
understand only C.

Provide an extern "C" linkage wrapper.

 

[flashdog]

Exist maybe a tool that creat such wrapper?

Provide an extern "C" linkage wrapper.

 

[Ian Collins]

flashdog wrote:

Please don't top-post.

Exist maybe a tool that creat such wrapper?

Your editor? Only you know what and how you want to call from C.

 

[Zeppe]

Exist maybe a tool that creat such wrapper?

please, do not top-post.

The thing is, there is no one-to-one correspondence between C and C++,
and in particular you cannot just automatically expose all your C++ code
as a C interface. I'm afraid the best solution is to think to a
reasonable C interface to your C++ code. That means, you will have a set
of "c-style" functions, with C linkage, that will internally use your
C++ code.

Best wishes,

Zeppe

 

[sean_in_raleigh]

Exist maybe a tool that creat such wrapper?

Check out SWIG: http://www.swig.org/

Sean

 

[Default User]

Hello,
how can I call this C++ Code from C? I must use C, because Ruby-ffi
understand only C.

<http://www.parashift.com/c++-faq-lite/mixing-c-and-cpp.html>




Brian