id	summary	reporter	owner	description	type	status	milestone	component	version	severity	resolution	keywords	cc
10443	[fusion] Compile errors with boost::fusion::invoke and boost::result_of using decltype	James Whitworth <fun4jimmy@…>	Joel de Guzman	"The following example fails to compile with c++11 compliant compilers.

{{{#!c++
#include <boost/bind.hpp>
#include <boost/function.hpp>

#include <boost/fusion/functional.hpp>

void Function( int & output )
{
  output = 12;
}

int main( int, char ** )
{
  boost::fusion::vector1< int > parameters;
  boost::function< void( int & ) > function = &Function;

  boost::fusion::invoke( function, parameters );

  return 0;
}
}}}

I think the problem is due to the implementation {{{boost::result}}} using decltype and {{{boost::fusion::invoke}}} expecting the old TR1 type behaviour. The example compiles fine when {{{BOOST_RESULT_OF_USE_TR1_WITH_DECLTYPE_FALLBACK}}} is defined.

Compiling the above with '''clang++ -std=c++11 main.cpp''' generates the following output:


{{{
In file included from main.cpp:4:
In file included from /usr/local/include/boost/fusion/functional.hpp:13:
In file included from /usr/local/include/boost/fusion/functional/invocation.hpp:13:
In file included from /usr/local/include/boost/fusion/functional/invocation/invoke.hpp:96:
In file included from /usr/local/include/boost/preprocessor/iteration/detail/iter/forward1.hpp:52:
/usr/local/include/boost/fusion/functional/invocation/invoke.hpp:205:55: error: no type named 'type' in 'boost::result_of<boost::function<void (int &)> (const int &)>'
                    Function(BOOST_PP_ENUM(N,M,~)) >::type result_type;
                    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~
/usr/local/include/boost/fusion/functional/invocation/invoke.hpp:161:38: note: in instantiation of template class 'boost::fusion::detail::invoke_impl<boost::function<void (int &)>, const boost::fusion::vector1<int>, 1, false, true>' requested here
            typedef typename detail::invoke_impl<
                                     ^
/usr/local/include/boost/fusion/functional/invocation/invoke.hpp:179:32: note: in instantiation of template class 'boost::fusion::result_of::invoke<boost::function<void (int &)>, const boost::fusion::vector1<int> >' requested here
    inline typename result_of::invoke<Function,Sequence const>::type
                               ^
/usr/local/include/boost/fusion/functional/invocation/invoke.hpp:180:5: note: while substituting deduced template arguments into function template 'invoke' [with Function = boost::function<void (int &)>, Sequence = boost::fusion::vector1<int>]
    invoke(Function f, Sequence const & s)
    ^
1 error generated.
}}}

"	Bugs	closed	To Be Determined	fusion	Boost 1.56.0	Problem	fixed	invoke result_of delctype c++11	jaredgrubb@… flast@…