ExceptionalC++ Fun: . Exception Safe code (copy constructor & copy assignment)

• a helper function can be used to copy and allocate memory, try catch, rethrow if something is wrong in that function

a nice style:

template

T* NewCopy( const T* src,

            size_t   srcsize,

            size_t   destsize )

{

  assert( destsize >= srcsize );

  T* dest = new T[destsize];

  try

  {

    copy( src, src+srcsize, dest );

  }

  catch(...)

  {

    delete[] dest; // this can't throw

    throw;         // rethrow original exception

  }

  return dest;

} 

 and use it:

template

Stack::Stack( const Stack& other )

  : v_(NewCopy( other.v_,

                other.vsize_,

                other.vsize_ )),

    vsize_(other.vsize_),

    vused_(other.vused_)

{

}