vector::insert segmentation fault

Question

I have a class like this:

classA
{
public:
  classA()
   {
     //Here I am doing something but nothing related to vector

   }

   void updateVec(int idx, i         


        

Answer 1

Segmentation fault means you're trying to access/write into memory that has not (yet) been allocated. In your case, depending on value of idx, myVec.begin() + idx can refer to memory that is out of vector's allocated zone. Before inserting, you need to make sure your vector can hold at least idx elements. updateVec should check the current size of the vector, and if it is not big enough, it should call vector::reserve to allocate enough room so new element can be inserted.