Subject: Re: [boost] [BGL] Visual Studio 12 finish_edge() failure, general BOOST_TTI_HAS_MEMBER_FUNCTION failure?
From: Michael Behrns-Miller (m_at_[hidden])
Date: 2014-04-01 04:40:31
On 3/31/2014 6:30 PM, Edward Diener wrote:
> On 3/31/2014 1:27 PM, Michael Behrns-Miller wrote:
>> ...
>> Here's how BGL defines it:
>>
>> -------------
>>
>> BOOST_TTI_HAS_MEMBER_FUNCTION(finish_edge)
>>
>> template <bool IsCallable> struct do_call_finish_edge {
>> template <typename E, typename G, typename Vis>
>> static void call_finish_edge(Vis& vis, const E& e, const G& g) {
>> vis.finish_edge(e, g);
>> }
>> };
>>
>> template <> struct do_call_finish_edge<false> {
>> template <typename E, typename G, typename Vis>
>> static void call_finish_edge(Vis&, const E&, const G&) {}
>> };
>>
>> template <typename E, typename G, typename Vis>
>> void call_finish_edge(Vis& vis, const E& e, const G& g) { // Only
>> call if method exists
>> do_call_finish_edge<has_member_function_finish_edge<Vis,
>> void>::value>::call_finish_edge(vis, e, g);
>> }
>
> The invocation of has_member_function_finish_edge has to match the
> member function signature which you are invoking. If the member
> function signature for finish_edge is:
>
> void finish_edge(const E&, const G&);
>
> then your invocation for do_call_finish_edge must be:
>
> do_call_finish_edge
> <
> has_member_function_finish_edge
> <
> Vis,
> void,
> boost::mpl::vector
> <
> const E&,
> const G&
> >
> >
> ::value
> >::call_finish_edge(vis, e, g);
>
> or
>
> do_call_finish_edge
> <
> has_member_function_finish_edge
> <
> void Vis::* (const E&,const G&)
> >
> ::value
> >::call_finish_edge(vis, e, g);
>
>
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Thank you Edward.
The instantiation code was not mine, that is what is done by the BGL, here:
boost\graph\depth_first_search.hpp
The instantiation code does not seem to match your recommendation. This
simple DFS test fails:
https://svn.boost.org/trac/boost/attachment/ticket/9770/test.cc
So it sounds like BGL needs some patching to match your format. It
should change from...
do_call_finish_edge<has_member_function_finish_edge<Vis,
void>::value>::call_finish_edge(vis, e, g);
to...
do_call_finish_edge<has_member_function_finish_edge<void Vis::* (const
E&,const G&)>::value>::call_finish_edge(vis, e, g);
Does that sound correct?