error: expected ')' before '*' token in header

Question

I am making a program where there is a Hero who has a Sword. I have a class for both of those. In the header I get the error: expected ')' before '*' token on the line Sword(Hero* h); in the header of Sword. Here is the compete file (Sword.h):

#ifndef SWORD_H
#define SWORD_H

#include <Hero.h>

class Sword {
    public:
        Sword(Hero* h);
        virtual ~Sword();
};

#endif // SWORD_H

Hero.h is in the same directory as Hero.h, and I'm using Code::Blocks.

I've looked through other posts and couldn't find anything that helped, so any given would be appreciated.

EDIT: Here is the content of Hero.h:

#ifndef HERO_H
#define HERO_H

#include <string>
#include <SDL.h>
#include <SDL_image.h>
#include <stdio.h>

#include <Sword.h>
#include <Sprite.h>
#include <Window.h>

class Hero : public Sprite {
    public:
        Hero(Window* w);
        void update();
        void event(SDL_Event e);
        ~Hero();
    protected:
    private:
        bool up;
        bool right;
        bool left;
        bool down;

        Window* window;
        Sword* sword;
};

#endif // HERO_H

Answer 1

You cannot include Sword.h from Hero.h and Hero.h from Sword.h, the inclusion chain has to stop somewhere. You can use a forward declaration to fix it:

//#include <Hero.h> // remove this

class Hero; // forward declaration

class Sword {
    public:
        Sword(Hero* h);
        virtual ~Sword();
};

This works because you don't need the definition of Hero in Sword.h. The compiler only needs to know that Hero is a class.

You can do the same in Hero.h: replace #include <Sword.h> with class Sword;. You can then include the files in the corresponding .cpp files where you need the definitions in order to use the classes.

Rule of thumb: always use forward declaration, unless the whole header needs to be included.

Further reading: When can I use a forward declaration?