Array of objects

SevenSegmentExtended    displays[] =
{
    SevenSegmentExtended(Disp1Ck, Disp1Io)
  , SevenSegmentExtended(Disp2Ck, Disp2Io)
  , SevenSegmentExtended(Disp3Ck, Disp3Io)
  , SevenSegmentExtended(Disp4Ck, Disp4Io)
};

Remember to call the 'begin' method for each item in the 'displays' array in your 'setup' before attempting to USE them.

EDITT: This creates an array of 'SevenSegmentExtended' objects so these are not pointers to the objects.