The case against digraphs and iso646.h

The NNI regrets that it has to vote against SC22/N1443.  The NNI does not wish to support the solution offered for the usage of C with national variants of the ISO 646 character set.  This solution is contained in clauses 2, 3 and 4.4 of N1443. 

There is pressure from countries using national variants of ISO 646 to have a standard way of expressing C in the invariant subset of ISO 646 that is more aesthetically pleasing than the trigraph solution that is embedded in the current C standard.  We understand their whish.  But we have come to the conclusion that we do not see an acceptable way of realizing this whish.  We see three criteria for proposed solutions: completeness, aesthetics and technical cleanness.

We would further like to make the following two observations:
  1. Usage of ISO 8859­1 (Latin­1), which solves this problem, is becoming widespread.

  2. We expect that the proposed solution will be little used.  Programs written in the ISO 646 invariant representation of C look so different from the current representation that they will be hard to maintain for people used to the current representation i.e the rest of the world.  We expect that for this reason a large part of the community in countries that stated interest in this proposal will keep on using the current representation of C. 
    Furthermore, only a few of the countries with national variants of ISO 646 have expressed interest in this proposal.
The proposal in clauses 2, 3 and 4.4 is not good enough to be acceptable, even as a compromise.  Especially because it solves a disappearing problem.  We see no reason to burden the international community with this part of N1443.

The rest of N1443 is a worthwhile document that we welcome. We will support N1443 if the objections mentioned above are taken away by removing the clauses 2, 3 and 4.4.