test.cpp

struct array_deleter
{
  void operator ()(char * p)
  { 
    delete[] p; 
  }
};

class A{
  public:
  shared_ptr<char> a;
  A() : a(new char[100], array_deleter()) {
  }
};

int main(int c, char* v) {
  shared_ptr<A> a(new A());
  ...
}