Re: [boost] [Fusion] Notice of breaking change

From: dan marsden (danmarsden_at_[hidden])
Date: 2007-06-13 03:02:00

shunsuke wrote:
>dan marsden wrote:
>> The above change has now been applied. Docs upgrades will follow in the next few days.
>
>The usage of boost::result_of is right?
>
>IIRC, for example, <transform_view/detail/apply_transform_result.hpp> should be
>
>
>             template <typename T0>
>             struct apply<T0, void_>
>                 : boost::result_of<F(typename add_reference<T0>::type)>
>             {};
>
>, because the object passed to a functor is lvalue.

I'm not sure about this. The function object f is called with f(*it). The dereference may return either l or rvalues depending
on its implementation. The Boost.ResultOf docs are not specific about passing T versus T&. Looking a the draft TR1 docs,
if Ti is a reference ti is an lvalue, otherwise it is an rvalue. As rvalues are possible, the above code looks correct. Assuming Boost.ResultOf
behaves like the TR1 spec, I think the above is ok(?)

It is possible this usage is not consistent correct across Fusion though. I'll have a review of the result_of usage shortly when I get a chance.

Thanks

Dan

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