Thread: class inheritance & vectors

  1. #1
    lv.42 Berserker Drake's Avatar
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    Talking class inheritance & vectors

    Hey, i'm making my final text rpg before I move onto direct x and i'm making great progress. I have created an inventory class and a vetor to hold Weapon objects. Now, the question I have to ask is: If I have created multiple classes that inherit all of Weapon's data members and functions(classes would include Sword, Bow, and Staff), would I be able to fill the vector with those classes?

    Ex:
    Code:
    vector<Weapon*> m_Weapons;
    
    void addW(Weapon* pWeapon);
    {
        m_Weapons.pushBack(pWeapon);
    }
    
    Inventory.addW(Sword)<-i have no idea how i would add in a sword object, would i have to cast?  I really don't know...
    thanks.

  2. #2
    semi-colon generator ChaosEngine's Avatar
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    for this kind of thing you really want either a boost.ptr_vector or a container or boost.shared_ptr's.

    your code would look something like

    Code:
    class Weapon
    {
    virtual void Strike(void) = 0;
    };
    class Sword : public Weapon {};
    class Staff : public Weapon {};
    class Bow : public Weapon {};
    class ThermoNuclearWarhead : public Weapon {};
    
    boost::ptr_vector<Weapon> m_weapons;
    
    m_weapons.push_back(new Sword);
    m_weapons.push_back(new Staff);
    m_weapons.push_back(new Bow);
    m_weapons.push_back(new ThermoNuclearWarhead);
    then you can use boost.bind to do even cooler stuff like
    Code:
    // call Strike() on each weapon polymorphically...
    std::for_each(m_weapons.begin(), m_weapons.end(),
                          boost::bind(&Weapon::Strike, _1);
    and that is the power of C++, mixing functional and OO techniques.

    edit: fixed code tags
    Last edited by ChaosEngine; 10-12-2006 at 07:07 PM.
    "I saw a sign that said 'Drink Canada Dry', so I started"
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  3. #3
    Registered User
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    Nice, ChaosEngine. I didn't know such things could be done...

  4. #4
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    >> i have no idea how i would add in a sword object, would i have to cast? I really don't know...
    No, you don't have to cast. Just past a pointer to a Sword if you want to add a Sword. The add function will work fine.

  5. #5
    lv.42 Berserker Drake's Avatar
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    Thumbs up

    thanks alot! I'll be sure to post the game in the games forum once it's complete.

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