Thread: Inserting pointer to an object in vector in a map

  1. #1
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    Inserting pointer to an object in vector in a map

    Hi, I would greatly appreciate if you could help me fixing this.

    So, a the simulation runs, different body parts represented by classes declared in the Player Class (e.g. Head, Body, Legs and Weapons) take damage. When this happens, I am storing a pointer to the damaged part in a map belonging to the player class, with the key value representing the priority in the subsequent repair queue:

    In the player class:

    Code:
    map<int, shared_ptr<PartBase>, greater<int>> DamageLog;
    Example of storage:

    Code:
    auto HeadPtr = std::make_shared<Part>(Head);
    if (Head.Critical > 0) DamageLog.insert(make_pair(200, HeadPtr));
    With 200 being a priority repair value;

    Each part is derived from PartBase and each overrides the Repair() method. At the end parts get repaired by calling:

    Code:
    for (auto const& item : player.DamageLog) item.second->Repair();
    Now, the PROBLEM is that Weapons are stored in an array belonging to Player Class

    Code:
    vector<shared_ptr<Weapon>> Loadout;
    and I cannot insert them in the map using:

    Code:
    for (auto weapon : Loadout) {
    	if (weapon->Disabled) {
    		auto WeaponPtr = std::make_shared<Weapon>(weapon);
    		DamageLog.insert(make_pair(10, WeaponPtr));
    	}
    }

  2. #2
    Programming Wraith GReaper's Avatar
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    So, you want multiple weapons to match on the same key? You can't do that with a map, I don't think. What you need is a multimap.
    Devoted my life to programming...

  3. #3
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    Quote Originally Posted by GReaper View Post
    So, you want multiple weapons to match on the same key? You can't do that with a map, I don't think. What you need is a multimap.
    No, I want each weapon to have a unique key. But, you are right, each iteration of the loop moves the same pointer to a new weapon. But how can I insert a copy of pointers to disabled weapons?

    Also, the line in loop is ment to read

    Code:
    auto WeaponPtr = weapon;
    And I think this was the error.
    Last edited by serge; 09-22-2019 at 12:59 PM.

  4. #4
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    One more question in this vein: Does

    Code:
    DamageLog.clear();
    kill all pointers? I am rewriting the log each game turn instead of updating it (for security). So I am clearing at the beginning of the log function.

  5. #5
    Informer -Adrian's Avatar
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    Clearing the map will free all the smart pointers it contains, yes.

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