C++: Shared_Ptr segfaults on virtual method call, but not dereference

Question

Currently my code looks like this:

class A
{
    public:
    //A(A&&);
    A& operator=(const A&);
    std::vector<std::shared_ptr<B>> myVec;

    int accessMyFunc() {
        return myVec[0]->myFunc();
    }
}

class B
{
    public:
    virtual ~B();
    virtual  int myFunc() const = 0;
}

class C : public B
{
    public:
    virtual int myFunc() const override {/* do stuff*/}
}

A makeanA()
{
    A temp;
    temp.myVec.emplace_back(new C)
    return temp;
}

When I run this main

int main()
{
    A theA;
    theA = makeanA();
    theA.accessMyFunc();
}

I get a segfault from the -> within accessMyFunc. However, *myVec[0] does not segfault, and I have checked within the assignment constructor for A that the shared_ptrs are being copied properly. Why would this segfault be occurring not on dereference, but on the method call? Especially when the assignment constructor verifies that the shared_ptr of the lhs and the rhs both point to the same spot?

Any help is appreciated.

Answer 1

So it ended up that my error was dealing with a dynamic/shared library. I opened the library within a function other than my main, so when the function returned, its attempts to find the virtual table resulted in a segfault