text: /* M_PI is defined in math.h in the case of Microsoft Visual C++, Solaris,
   * et. al.
   */
  #if defined(_MSC_VER)
  #define _USE_MATH_DEFINES
  #endif 
  
  #include <string>
  #include <iostream>
  #include <cairommconfig.h>
  #include <cairomm/context.h>
  #include <cairomm/surface.h>
  
  #include <cmath>
  
  int main()
  {
      auto surface =
          Cairo::ImageSurface::create(Cairo::FORMAT_ARGB32, 600, 400);
  
      auto cr = Cairo::Context::create(surface);
  
      cr->save(); // save the state of the context
      cr->set_source_rgb(0.86, 0.85, 0.47);
      cr->paint();    // fill image with the color
      cr->restore();  // color is back to black now
  
      cr->save();
      // draw a border around the image
      cr->set_line_width(20.0);    // make the line wider
      cr->rectangle(0.0, 0.0, surface->get_width(), surface->get_height());
      cr->stroke();
  
      cr->set_source_rgba(0.0, 0.0, 0.0, 0.7);
      // draw a circle in the center of the image
      cr->arc(surface->get_width() / 2.0, surface->get_height() / 2.0, 
              surface->get_height() / 4.0, 0.0, 2.0 * M_PI);
      cr->stroke();
  
      // draw a diagonal line
      cr->move_to(surface->get_width() / 4.0, surface->get_height() / 4.0);
      cr->line_to(surface->get_width() * 3.0 / 4.0, surface->get_height() * 3.0 / 4.0);
      cr->stroke();
      cr->restore();
  
  #ifdef CAIRO_HAS_PNG_FUNCTIONS
  
      std::string filename = "image.png";
      surface->write_to_png(filename);
  
      std::cout << "Wrote png file \"" << filename << "\"" << std::endl;
  
  #else
  
      std::cout << "You must compile cairo with PNG support for this example to work."
          << std::endl;
  
  #endif
  }
  