How to use find algorithm with a vector of pointers to objects in c++?

Question

I want to find in a vector of Object pointers for a matching object. Here\'s a sample code to illustrate my problem:

class A {
public:
    A(string a):_a(a) {}
          


        

Answer 1

Use find_if with a functor:

template 
struct pointer_values_equal
{
    const T* to_find;

    bool operator()(const T* other) const
    {
        return *to_find == *other;
    }
};


// usage:
void test(const vector& va)
{
    A* to_find = new A("two");
    pointer_values_equal eq = { to_find };
    find_if(va.begin(), va.end(), eq);
    // don't forget to delete A!
}

Note: your operator== for A ought to be const, or, better still, write it as a non-member friend function.