Boost: what is a "convenience header"?

Question

What is the difference between "header" and "convenience header" in boost?

Answer 1

A convenience header is typically (not just in Boost) a header which includes a number of other headers (that contain actual code) which are commonly used together, even though there are no hard dependencies between them (which is why they're separate in the first place).

Answer 2

It includes a lot of different but related headers

For example boost/smart_ptr.hpp includes shared and scoped pointer containers:

//
//  smart_ptr.hpp
//
//  For convenience, this header includes the rest of the smart
//  pointer library headers.
//
//  Copyright (c) 2003 Peter Dimov  Distributed under the Boost
//  Software License, Version 1.0. (See accompanying file
//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
//  http://www.boost.org/libs/smart_ptr/smart_ptr.htm
//

#include <boost/config.hpp>

#include <boost/scoped_ptr.hpp>
#include <boost/scoped_array.hpp>
#include <boost/shared_ptr.hpp>
#include <boost/shared_array.hpp>

#if !defined(BOOST_NO_MEMBER_TEMPLATES) || defined(BOOST_MSVC6_MEMBER_TEMPLATES)
# include <boost/weak_ptr.hpp>
# include <boost/intrusive_ptr.hpp>
# include <boost/enable_shared_from_this.hpp>
#endif