namespace
boost
{
template <class T>
---unspecified--- enable_error_info( T const & x );
}
Requirements:
T must be a class with an accessible no-throw copy constructor as per (15.5.1).
Returns:
If T derives from boost::exception, the returned object is of type T and is a copy of x.
Otherwise, the returned object is of an unspecified type that derives publicly from both T and boost::exception. The T sub-object is initialized from x by the T copy constructor.