Re: [Boost-users] Equality comparison of boost::function<>

AMDG Zachary Turner wrote:

On Mon, Aug 10, 2009 at 10:51 AM, Steven Watanabe wrote:

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This ought to return false because the types are different.

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So in short, what is the flaw in just testing the way two function objects are represented internally

It would be surprising, because nothing else works that way.

I agree it might be surprising from an implementation standpoint. But are there examples of functors such that equality implemented this way would return a surprising result?

boost::lambda::_1 == std::string() The result of memcmp depends on the implementation details of std::string.

If the result isn't surprising, then I don't think the implementation should matter much, as long as it relies only on standards conformant language aspects.

memcmp is not guaranteed to produce sensible results in this context. I don't know that it is even guaranteed to work for POD types, when padding is added for alignment reasons.

Again I could just be overlooking something due to lack of understanding of the implementation details of boost::function<>, but at least on the surface it seems to me that the behavior would always produce expected results

In Christ, Steven Watanabe