Re: Number/Algebraic concepts (was RE: [boost] RE: rational.hpp)

From: Jeremy Siek (jsiek_at_[hidden])
Date: 2001-01-14 20:59:50

That's a good question. I think the named conformance checking could work
well for the semantic information, and could easy be added to the
structural concept checks. However, I'd like to see something much simpler
than what is in the Algebra library... something along the lines of

is_associative<Domain, Op>::type   (true_type or false_type)
                          ::value  (true or false)

Then use this in a static assert in the appropriate concept checking
classes.

It would be nice if we could have a fairly portable system, works
with VC++, Borland, etc. That means no partial spec. :(

Cheers,
Jeremy

On Sun, 14 Jan 2001, Doug Gregor wrote:
gregod> Does Boost need named conformance checking? It can help
gregod> assure correctness of programs better than structural
gregod> conformance, but it raises the bar significantly for
gregod> users. I wonder how useful algebraic concepts are without
gregod> named conformance as most of the usefulness of the algebra
gregod> concept hierarchy is in the semantic information. Both
gregod> BOOST_CLASS_REQUIRES(Domain, Op, Associative) and
gregod> BOOST_CLASS_REQUIRES(Domain, Op, BinaryOp) perform the
gregod> same structural concept checks, but the first has a much
gregod> stronger semantic condition.

----------------------------------------------------------------------
 Jeremy Siek                        www: http://www.lsc.nd.edu/~jsiek/
 Ph.D. Candidate                  email: jsiek_at_[hidden]
 Univ. of Notre Dame         work phone: [phone]
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