c++ – Compile error on virtual inheritance using multi_index_container

Question:

#include <boost/multi_index_container.hpp>
#include <boost/multi_index/hashed_index.hpp>
#include <boost/multi_index/mem_fun.hpp>

namespace mi = boost::multi_index;


namespace vo {

class Statable {};

class Entity : virtual public Statable {};

} /* namespace vo */

class Statable : virtual public vo::Statable {};

class Entity
    : virtual public vo::Entity
    , public Statable
{
    std::string name_;

public:
    std::string const& name() const { return name_; }

private:
    typedef mi::multi_index_container <
      Entity*
    , mi::indexed_by<mi::hashed_unique<mi::const_mem_fun<Entity, std::string const&, &Entity::name> > >
    > nested_objects_t;

    nested_objects_t nested_objects_;
};

Good day! With such a code architecture (this is a simplified example, of course), compilation breaks with an error:

Error C1001 An internal error has occurred in the compiler

Trial and error revealed that the problem is in the line:

mi::hashed_unique<mi::const_mem_fun<Entity, std::string const&, &Entity::name> >

This problem only occurs when virtual inheritance is present! Those. if now Entity is made only a successor from ::Statable (remove virtual public vo::Entity), and in turn make it a regular successor from vo::Statable (without virtual public), then the error will disappear.

Also, the error will disappear if you just take out the typedef outside the Entity class!

Why is this happening, I can not understand in any way?

PS Tried in VS2010, VS2012, VS2015 with various boost versions from 1.33 to 1.68

Answer:

I reproduced this error even in a simpler example. It is enough to have virtual inheritance in the top class Entity for it to occur. The base class is enough one, any.

However, after adding

#pragma pointers_to_members(full_generality)

the error is gone. I haven't checked if this results in the full functionality of your code, however, when dealing with pointers to class members under multiple and virtual inheritance conditions in MSVC++, I would recommend always setting these options to the most "safe" option.