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

From: Jeremy Siek (jsiek_at_[hidden])
Date: 2001-01-14 22:51:36

I don't see a benefit of the inheritance hierarchy for boost purposes. You
say the benefit is that it reduces checking to a pointer conversion...
but this makes little difference because causing the compiler error is
easy. We could just as easily use boost static assert with is_associative.

  template <class Domain, class Op>
  class AssociativeConcept {
  public:
    void constraints() {
      function_requires< BinaryOpConcept<Domain, Op> >();
      BOOST_STATIC_ASSERT(is_associative<Domain, OP>::value);
    }
  };

It looks like the above gets the job done, and is extremely simple.

Are there other advantages to the inheritance hierarchy?

On Sun, 14 Jan 2001, Doug Gregor wrote:
gregod> In any case, for named conformance concept checking I
gregod> would suggest representing a concept lattice as an
gregod> inheritance hierarchy. Then, checking named conformance
gregod> (taking subconcepts into account) reduces to checking a
gregod> pointer conversion similarly to Boost's is_convertible.
gregod> Unfortunately, the

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 Jeremy Siek                        www: http://www.lsc.nd.edu/~jsiek/
 Ph.D. Candidate                  email: jsiek_at_[hidden]
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