C++ class forward declaration

Question

When I try to compile this code i get:

52 C:\\Dev-Cpp\\Projektyyy\\strategy\\Tiles.h invalid use of undefined type `struct tile_tree_apple\' 
46 C:\\Dev-Cpp\         


        

Answer 1

class tile_tree_apple should be defined in a separate .h file.

tta.h:
#include "tile.h"

class tile_tree_apple : public tile
{
      public:
          tile onDestroy() {return *new tile_grass;};
          tile tick() {if (rand()%20==0) return *new tile_tree;};
          void onCreate() {health=rand()%5+4; type=TILET_TREE_APPLE;}; 
          tile onUse() {return *new tile_tree;};       
};

file tt.h
#include "tile.h"

class tile_tree : public tile
{
      public:
          tile onDestroy() {return *new tile_grass;};
          tile tick() {if (rand()%20==0) return *new tile_tree_apple;};
          void onCreate() {health=rand()%5+4; type=TILET_TREE;};        
};

another thing: returning a tile and not a tile reference is not a good idea, unless a tile is a primitive or very "small" type.