Boost C++ Application Development Cookbook - Second Edition

How to do it...

The Boost.Utility library provides a quick solution for such cases. Solution is called the boost::base_from_member template. To use it, you need to carry out the following steps:

1. Include the base_from_member.hpp header:

#include <boost/utility/base_from_member.hpp>

2. Derive your class from boost::base_from_member<T> where T is a type that must be initialized before the base (take care about the order of the base classes; boost::base_from_member<T> must be placed before the class that uses T):

class fake_tasks_processor_fixed    : boost::base_from_member<std::ostringstream>    , public tasks_processor

3. Correctly, write the constructor as follows:

{    typedef boost::base_from_member<std::ostringstream> logger_t; virtual void do_process() ...