recursive_wrapper and ambiguous convert_construct() [closed] - c++

Question

Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers.
This question appears to be off-topic because it lacks sufficient information to diagnose the problem. Describe your problem in more detail or include a minimal example in the question itself.
Closed 9 years ago.
Improve this question
Do you have any idea how to solve or get around this problem?
http://boost.2283326.n4.nabble.com/Variant-recursive-wrapper-and-ambiguous-convert-construct-td4543139.html
#include <boost/variant.hpp>
class b_fwd;
typedef boost::variant<boost::recursive_wrapper<b_fwd> > a;
class c_fwd;
typedef boost::variant<boost::recursive_wrapper<c_fwd> > b;
struct b_fwd : b {
// inherit constructors
template <typename... Ts> b_fwd(Ts... o) : b(o...) {}
};
typedef boost::variant<double, char *> c;
struct c_fwd : c {
// inherit constructors
template <typename... Ts> c_fwd(Ts... o) : c(o...) {}
};
void f(const b &b_node)
{
a a_node(b_node);
}
int main()
{
}

Answer 1

I had a hunch in reaction to GuyGreer's comment.
If the problem is caused by variant being assignable/convertible to variant, then maybe we can disambiguate by using a third, isolated, variant:
a a_node(boost::variant<b>(b_node));
Lo and behold, homeopathy seems to work :)
See it Live On Coliru
I have no idea whether this "works" in the sense that the OP expects, because, frankly, the OP's code was a mystery to me
#include <boost/variant.hpp>
class b_fwd;
typedef boost::variant<boost::recursive_wrapper<b_fwd> > a;
class c_fwd;
typedef boost::variant<boost::recursive_wrapper<c_fwd> > b;
struct b_fwd : b {
using b::b;
};
typedef boost::variant<double, char *> c;
struct c_fwd : c {
using c::c;
};
void f(const b &b_node)
{
a a_node(boost::variant<b>(b_node));
}
int main()
{
}