incomplete type and cannot be defined

[iamhere]

Hi, im having problems with a project I am working on. It is a class that creates an xlib window. Here is the code:

main.cpp

#include <X11/Xlib.h>
#include "ys_window.h"

int main(){

    //window object
    ys_window wind;

    wind.showwindow(true);

    while(1){
        XEvent e;
    }

    return 0;
}

ys_window.h

#ifndef YS_WINDOW_H_INCLUDED
#define YS_WINDOW_H_INCLUDED

    class ys_window;

#endif // YS_WINDOW_H_INCLUDED

ys_window.cpp

#include <X11/Xlib.h>
#include <cairo.h>
#include <cairo-xlib.h>

class ys_window{
    private:
        int xsize;
        int ysize;
        int xpos;
        int ypos;

        bool visible;

        //cairo variables
        cairo_surface_t *cs;
        cairo_t *c;

        //xlib variables
        Display *dpy;
        int blackcolour;
        Window w;

    public:
        ys_window(){
            //set the default values to create the window
            xsize = 200;
            ysize = 200;
            xpos = 200;
            ypos = 200;

            //the xlib display variable
            dpy = XOpenDisplay(0);

            //colour used to blackout the window
            blackcolour = BlackPixel(dpy, DefaultScreen(dpy));

            //create the window
            w = XCreateSimpleWindow(dpy, DefaultRootWindow(dpy), xpos, ypos, xsize, ysize, 0, blackcolour, blackcolour);

            XFlush(dpy);

        };

        void showwindow(bool visible);
};

void ys_window::showwindow(bool vis)
{
    if(vis == true){

        XMapWindow(dpy, w);

    }else{

        XUnmapWindow(dpy, w);

    }

    XFlush(dpy);
    visible = vis;
}

I keep getting the error "/root/Development/ys_framework/main.cpp|7|error: aggregate ‘ys_window wind’ has incomplete type and cannot be defined|"