C++ Uninitialized memory?

Question

I am sometimes (randomly) getting incorrect initialization of values, which makes me think I'm using memory uninitialized somewhere. My main data structure is:

template <class state>
class learnedStateData {
public:
    learnedStateData() :gCost(DBL_MAX), hCost(0), isDead(false) {}
    state theState;
    double gCost;
    double hCost;
    bool isDead;
};

This is being stored in a STL hash_map. Any thoughts on how I might get uninitialized data (besides the theState) from this data structure?

Let me clarify: I don't want my values to be uninitialized, but they appear to be randomly at times.

Answer 1

The implementation is perfectly sound... your issue must be elsewhere. You could use a tool like valgrind to check for invalid memory accesses, uninitialised reads etc.. You could add some assertions to try to narrow down the point where the state is corrupted. If you provide a hash algorithm, make sure it returns the same value consistently for the same key value. Check you don't somehow modify the key of an object while it's inside the container. You might swap in a std::map<> and see if the problem disappears.

Answer 2

You have not initialized theState inside the constructor

Use Value Initialization

template <class state>
class learnedStateData {
public:
    learnedStateData() :theState(),gCost(DBL_MAX), hCost(), isDead() {}
    state theState;        ^                         ^          ^
    double gCost;          |_________________________|__________|
    double hCost;                            |
    bool isDead;                        Value Initialized
};