1 // (C) Copyright 2008 CodeRage, LLC (turkanis at coderage dot com)
2 // (C) Copyright 2003-2007 Jonathan Turkanis
3 // Distributed under the Boost Software License, Version 1.0. (See accompanying
4 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt.)
5 
6 // See http://www.boost.org/libs/iostreams for documentation.
7 
8 #ifndef BOOST_IOSTREAMS_PIPABLE_HPP_INCLUDED
9 #define BOOST_IOSTREAMS_PIPABLE_HPP_INCLUDED
10 
11 #if defined(_MSC_VER)
12 # pragma once
13 #endif
14 
15 #include <boost/config.hpp> // BOOST_MSVC.
16 #include <boost/detail/workaround.hpp>
17 #include <boost/iostreams/detail/template_params.hpp>
18 #include <boost/iostreams/traits.hpp>
19 #include <boost/mpl/bool.hpp>
20 #include <boost/preprocessor/punctuation/comma_if.hpp>
21 #include <boost/preprocessor/repetition/enum_params.hpp>
22 #include <boost/static_assert.hpp>
23 
24 #define BOOST_IOSTREAMS_PIPABLE(filter, arity) \
25     template< BOOST_PP_ENUM_PARAMS(arity, typename T) \
26               BOOST_PP_COMMA_IF(arity) typename Component> \
27     ::boost::iostreams::pipeline< \
28         ::boost::iostreams::detail::pipeline_segment< \
29             filter BOOST_IOSTREAMS_TEMPLATE_ARGS(arity, T) \
30         >, \
31         Component \
32     > operator|( const filter BOOST_IOSTREAMS_TEMPLATE_ARGS(arity, T)& f, \
33                  const Component& c ) \
34     { \
35         typedef ::boost::iostreams::detail::pipeline_segment< \
36                     filter BOOST_IOSTREAMS_TEMPLATE_ARGS(arity, T) \
37                 > segment; \
38         return ::boost::iostreams::pipeline<segment, Component> \
39                    (segment(f), c); \
40     } \
41     /**/
42 
43 namespace boost { namespace iostreams {
44 
45 template<typename Pipeline, typename Component>
46 struct pipeline;
47 
48 namespace detail {
49 
50 #if BOOST_WORKAROUND(__BORLANDC__, < 0x600)
51     template<typename T>
52     struct is_pipeline : mpl::false_ { };
53 
54     template<typename Pipeline, typename Component>
55     struct is_pipeline< pipeline<Pipeline, Component> > : mpl::true_ { };
56 #endif
57 
58 template<typename Component>
59 class pipeline_segment
60 {
61 public:
pipeline_segment(const Component & component)62     pipeline_segment(const Component& component)
63         : component_(component)
64         { }
65     template<typename Fn>
for_each(Fn fn) const66     void for_each(Fn fn) const { fn(component_); }
67     template<typename Chain>
push(Chain & chn) const68     void push(Chain& chn) const { chn.push(component_); }
69 private:
70     pipeline_segment operator=(const pipeline_segment&);
71     const Component& component_;
72 };
73 
74 } // End namespace detail.
75 
76 //------------------Definition of Pipeline------------------------------------//
77 
78 template<typename Pipeline, typename Component>
79 struct pipeline : Pipeline {
80     typedef Pipeline   pipeline_type;
81     typedef Component  component_type;
pipelineboost::iostreams::pipeline82     pipeline(const Pipeline& p, const Component& component)
83         : Pipeline(p), component_(component)
84         { }
85     template<typename Fn>
for_eachboost::iostreams::pipeline86     void for_each(Fn fn) const
87     {
88         Pipeline::for_each(fn);
89         fn(component_);
90     }
91     template<typename Chain>
pushboost::iostreams::pipeline92     void push(Chain& chn) const
93     {
94         Pipeline::push(chn);
95         chn.push(component_);
96     }
tailboost::iostreams::pipeline97     const Pipeline& tail() const { return *this; }
headboost::iostreams::pipeline98     const Component& head() const { return component_; }
99 private:
100     pipeline operator=(const pipeline&);
101     const Component& component_;
102 };
103 
104 template<typename Pipeline, typename Filter, typename Component>
105 pipeline<pipeline<Pipeline, Filter>, Component>
operator |(const pipeline<Pipeline,Filter> & p,const Component & cmp)106 operator|(const pipeline<Pipeline, Filter>& p, const Component& cmp)
107 {
108     BOOST_STATIC_ASSERT(is_filter<Filter>::value);
109     return pipeline<pipeline<Pipeline, Filter>, Component>(p, cmp);
110 }
111 
112 } } // End namespaces iostreams, boost.
113 
114 #endif // #ifndef BOOST_IOSTREAMS_PIPABLE_HPP_INCLUDED
115