Question

I have a vector of pointers to objects QActionDonald and I’m trying to find the object containing the highest expectedvalue_. I have overloaded the operator< and I’m using the max_element method to obtain an iterator to the highest value but i always receive the end value which is not correct.
QActionDonald.h:

class QActionDonald
{
public:

double expectedvalue_;

bool operator < (const QActionDonald& other) const;

}; 

QActionDonald.cpp:

bool QActionDonald::operator< (const QActionDonald& other) const
{
    return expectedvalue_ < other.expectedvalue_;
}

otherClass:

std::vector<QActionDonald*> *actionList =  qValueDictionary[stateKey];

        std::vector<QActionDonald*>::iterator it = 
std::max_element(actionList->begin(), actionList->end());

Answer 1

Of course it’s not, because your container has pointers, not objects.

For it to be used, you’ll need std::vector<QActionDonald> or, if that’s not subject to change, to provide a custom comparator to std::max_element that applies the correct logic (i.e. compare objects, not pointers).