what_s_new.qbk

来自「Boost provides free peer-reviewed portab」· QBK 代码 · 共 46 行

[/==============================================================================
    Copyright (C) 2001-2008 Joel de Guzman
    Copyright (C) 2001-2008 Hartmut Kaiser

    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)
===============================================================================/]

[section What's New]

[heading Spirit Classic]

The Spirit V1.8.x code base has been integrated with Spirit V2. It is now called
__classic__. Even if the directory structure has changed (the Spirit Classic
headers are now moved to the '''$BOOST_ROOT/boost/spirit/home/classic''' directory),
we created forwarding headers allowing to compile existing applications without
any change. These forwarding headers are deprecated, though, which will result
in corresponding warnings generated for each of the headers starting with Boost
V1.38. The forwarding headers are expected to be removed in the future.

The recommended way of using Spirit Classic now is to include header files from
the directory '''$BOOST_ROOT/boost/spirit/include'''. All files of Spirit Classic
in this directory have a 'classic_' prefixed to their name. For example the
include

    #include <boost/spirit/core/core.hpp>

now should be written as:

    #include <boost/spirit/include/classic_core.hpp>

To avoid namespace conflicts with the new Spirit V2 library we moved Spirit Classic
into the namespace `boost::spirit::classic`. All references to the former
namespace `boost::spirit` need to be adjusted as soon as the header names are
corrected as described above. As an alternative you can define the preprocessor
constant `BOOST_SPIRIT_USE_OLD_NAMESPACE`, which will force the Spirit Classic
code to be in the namespace `boost::spirit` as before. This is not recommended,
though, as it may result in naming clashes.

The change of the namespace will be automatically deactivated whenever the
deprecated include files are being used. This ensures full backwards
compatibility for existing applications.


[endsect]