Question

maybe you can help me get this right.
I have a class that is used to draw a circle, but the compiler sends me this message:

In file included from ./Includes.h:19,
                 from ./Circle.h:8,
                 from ./Circle.cpp:5:
./GameApp.h:24: error: ISO C++ forbids declaration of 'Circle' with no type
./GameApp.h:24: error: expected ';' before '*' token

Here is the GameApp.h:

#include "Includes.h"

class GameApp {

public:
 GameApp();
 ~GameApp();
 void Render();

protected:
 void InitGU();
 bool Controls();

 void *dList;  // display List, used by sceGUStart
 void *fbp0;  // frame buffer

 Circle* circle;
};

The Include.h looks like this:

//************************************************************************
//                              Includes.h
//************************************************************************

#include <malloc.h>     //For memalign()
#include <pspkernel.h>
#include <pspdisplay.h>
#include <pspdebug.h>
#include <stdio.h>
#include <psprtc.h>             // for the timer/fps functions
#include <pspctrl.h>
#include <math.h>

// GU
#include <pspgu.h>
#include <pspgum.h>

// Custom
#include "GameApp.h"
#include "Circle.h"


//************************************************************************

// Definitions
#define BUF_WIDTH (512)
#define SCR_WIDTH (480)
#define SCR_HEIGHT (272)

#define sin_d(x) (sin((x)*M_PI/180))
#define cos_d(x) (cos((x)*M_PI/180))
#define tan_d(x) (tan((x)*M_PI/180)) 

//************************************************************************

// structs, datatypes...
#ifndef VERTEX_TYPE_
#define VERTEX_TYPE_
typedef struct {
    unsigned int color;
    float x, y, z;
} vertex;
#endif

And the Circle.h

//************************************************************************
//                              Circle.h
//************************************************************************

#ifndef CIRCLE_H_
#define CIRCLE_H_

#include "Includes.h"

class Circle {

public:
    Circle(float r1);
    ~Circle();
    void Render();

    float r;
    float x, y;
    float vx, vy;

protected:
    vertex* vertices;
    int n;

};

#endif

Answer 1

Do not use one-massive-include-to-include-everything (except for precompiled headers). It will almost certainly result in headaches.

Include what you need, and no more. It will solve your problem.

You can forward declare Circle, as DanDan suggested, but fixing your inclusion problem will help you more in the long run.