Nested boost::fusion::make_list fails to compile under boost 1.58.0

[Andrew King <eurokang@…>]

The following code compiles just fine under boost 1.56.0 (std=c++11), but fails to compile under boost-1.58.0 with either clang++-3.6 or g++-4.9.2

#include <boost/fusion/container/generation/make_list.hpp>
#include <boost/fusion/algorithm/iteration/for_each.hpp>
#include <iostream>

template <typename T>
void Handle(const T& t);

template <typename ... T>
void Handle(const boost::fusion::list<T...>& x);

struct CallFunctor
{
    template <typename T>
    void operator()(const T& t) const
    {
        Handle(t);
    }
};

template <typename T>
void Handle(const T& t)
{
    std::cout << t << std::endl;
}

template <typename ... T>
void Handle(const boost::fusion::list<T...>& x)
{
    boost::fusion::for_each(x, CallFunctor{});
}

template <typename List>
void PrintList(const List& list)
{
    boost::fusion::for_each(list, CallFunctor{});
}

int main()
{
    PrintList(
        boost::fusion::make_list(
            std::string("x"),
            4,
            6,
            boost::fusion::make_list(23.0, std::string("rar"))));

    return 0;
}

There appears to be a compile error with the use of boost::is_convertible inside boost::enable_if in boost/fusion/container/list/cons.hpp:79

[Kohei Takahashi <flast@…>]

Reduced.

#include <boost/fusion/container/generation/make_list.hpp>

int main()
{
    boost::fusion::make_list(boost::fusion::make_list(42));
}

and it relates to constexpr ctor since compiles with -DBOOST_NO_CXX11_CONSTEXPR.

[Kohei Takahashi <flast@…>]

Fixed by ​https://github.com/boostorg/fusion/pull/79.