Hello everyone.
I have finally created an inventory for my RPG game, right now It can do:

-> Show the items I have in a 20 slot inventory.
-> Show the icon of the item
-> Show the description (3 lines max)

Here is how it looks now:

{"name":"at18.png","src":"\/\/djungxnpq2nug.cloudfront.net\/image\/cache\/e\/0\/e0ca6a4ca3e8a6cbf411a05ef11c1ee6.png","w":636,"h":476,"tn":"\/\/djungxnpq2nug.cloudfront.net\/image\/cache\/e\/0\/e0ca6a4ca3e8a6cbf411a05ef11c1ee6"}

But, as you can see I have many potions on my inventory, what I want to do is to use only 1 slot for them, I mean have a "stack" of items, a number will show the quantity of items I have. Like that:

{"name":"3vg5.png","src":"\/\/djungxnpq2nug.cloudfront.net\/image\/cache\/c\/e\/ce647b46fa8d611541f39a0f30dd237a.png","w":636,"h":476,"tn":"\/\/djungxnpq2nug.cloudfront.net\/image\/cache\/c\/e\/ce647b46fa8d611541f39a0f30dd237a"}

I have tried to do that, but no success, here is my code for the Scene_Inventory class:

The last function is the one I am talking about, this is how it should work:
1- Check if the player has the item (itemname.have)
2- If the player doesn't has the item, then we add a new element to the vector with the item name provided. Then increment the quantity by 1, then set "have" to true.
3- If the player has the item, then just increment it's quantity by 1.

Please help me, I really don't know how to do that, the function doesn't work...

Thank you very much

Thanks for the reply.

Well, I call the function like that:

The vector takes the actual item... Maybe there is something that I'm not doing correct.
Maybe I'm not passing correctly the item to the function..

I'm really stuck with this :S

Thanks for the example.
But I can't use Inventory.size() because at the start the vector is empty, so I'm getting an "out of range" error...

I tried to switch Inventory.size() to 20, in line 3 of your code and anyway get the error...

Oh, right. Sorry, my bad.

make that

int Scene_Inventory::containsItem(Item &itemname)
{
   if(!Inventory.empty())
   {
      for(int i=0; i<Inventory.size(); i++)
      {
         if(Inventory.at(i).name==itemname.name)// i.e. "potion" or "gold ring" (use string class for name)
            return i;//return position of Item of same type as itemname
      }
   }
   return -1;
}

EDIT:
Or do what Edgar said

If name is now a std::string, use name.c_str() to convert it into a const char * array.

You could register classes of items with a registry. And if you wanted stackable inventory, you could use a multimap which allows you to have multiple copies of the key (item) and since you store an int then that is the count of the item in that 'pile'.