C constant expressions proposals

[Gabriel Dos Reis]

"Joseph S. Myers" <jsm@polyomino.org.uk> writes:

| I have now prepared detailed semi-formal models of the interpretation of 
| the C constant expression rules, and their extension to GNU C, along with 
| ordinary English text descriptions of those extensions to constant 
| expressions that are de facto present in GNU C (as part of the present 
| "whatever the compiler of the day happens to fold to a constant is 
| constant") and which seem likely to have been widely used or the 
| preservation of which has been specifically requested in past discussions 
| of constant expressions.  Also included are some notes on the benefits 
| naturally associated with implementation of well-defined constant 
| expression rules, apart from better conformance.
| 
| http://www.srcf.ucam.org/~jsm28/gcc/#const
| 
| Feedback welcome on these models; the (newly revised and expanded) 
| discussion of problems with constant expression rules in C99; the 
| particular extensions that should be accepted in GNU C; and anything else 
| about these proposals.

I would like to mention the following proposal

  Generalized Constant Expressions
  http://www.open-std.org/JTC1/SC22/WG21/docs/papers/2003/n1521.pdf

that has been well received and encouraged at the Kona meeting of the
C++ standards meeting. I believe, in all modesty, that it is a
extension worth having in GNU C and GNU C++, pending final vote from
the C++ standards committee.

-- Gaby