works for me

$ cat vector_inherits.cpp

#include <vector>
#include <iostream>
#include <exception>
template <class T, class A = std::allocator<T> >
class MyVector : public std::vector<T,A>
{
public:
 const T & operator[](typename std::vector<T,A>::size_type i) const {
 if (i >= std::vector<T,A>::size()) throw std::exception();
 return std::vector<T,A>::operator[](i);
 }
};
int main()
{
 MyVector<int> v;
 v.push_back(5);
 try {
 std::cout << v[1] << std::endl;
 } catch (const std::exception & e) {
 std::cout << "received exception" << std::endl;
 return 1;
 }
 return 0;
}