SUBSREF SUBSREF Overloaded Class Indexing

Usage

This method is called for expressions of the form

  c = a(b), c = a{b}, c = a.b

and overloading the subsref method allows you
to define the meaning of these expressions for
objects of class a.  These expressions are
mapped to a call of the form

  b = subsref(a,s)

where s is a structure array with two fields. The
first field is
  -  type  is a string containing either '()' or
 '{}' or '.' depending on the form of the call.

  -  subs is a cell array or string containing the
 the subscript information.

When multiple indexing experssions are combined together
such as b = a(5).foo{:}, the s array contains
the following entries

  s(1).type = '()'  s(1).subs = {5}
  s(2).type = '.'   s(2).subs = 'foo'
  s(3).type = '{}'  s(3).subs = ':'

