I have a class definition of the form

class X
{
  public:
     //class functions
  private:
      A_type *A;
      //other class variables
};

and struct A_type is defined as

struct A_type
{ 
  string s1,s2,s3;
};

Inside the constructor, I allocate appropriate memory for A and try A[0].s1="somestring"; It shows segmentation fault. Is this kind of declaration invalid, or am I missing something