[GiNaC-devel] is_exactly_a

[Vladimir V. Kisil]

	Dear Jan,
>>>>> On Mon, 19 Jun 2017 18:24:21 +0200, Jan Rheinländer <jrheinlaender at gmx.de> said:
    JR> In contrast, 'is_exactly_a<T>(e)' allows you to check whether
    JR> the top-level object of an expression 'e' is an instance of the
    JR> GiNaC class 'T', not including parent classes.

    JR> Shouldn't this read "not including subclasses"? Otherwise, I
    JR> don't understand what the documentation wants to say.

    Consider:

	varidx k(symbol("k"),2);
	cout << is_a<idx>(k) << endl; // -> 1
	cout << is_exactly_a<idx>(k) << endl; // -> 0

  So, varidx k is an instance of idx, but not exactly idx---since the
  parent class idx of the class varidx is not included in the test
  is_exactly_a. The wording seems to be right to me.

  Best wishes,
  Vladimir
-- 
Vladimir V. Kisil                 http://www.maths.leeds.ac.uk/~kisilv/
  Book:     Geometry of Mobius Transformations     http://goo.gl/EaG2Vu
  Software: Geometry of cycles          http://moebinv.sourceforge.net/