Boost Exception

errinfo_nested_exception

#include <boost/exception/errinfo_nested_exception.hpp>

#include <boost/exception/error_info.hpp>

namespace
boost
    {
    typedef ---unspecified--- exception_ptr;
    typedef error_info<struct errinfo_nested_exception_,exception_ptr> errinfo_nested_exception;
    }

This type is designed to be used as a standard error_info instance for transporting (in exceptions deriving from boost::exception) an exception_ptr to an exception nested into another exception.