source: NonGTP/Boost/boost/iostreams/pipeline.hpp @ 857

Revision 857, 3.9 KB checked in by igarcia, 19 years ago (diff)
Line 
1// (C) Copyright Jonathan Turkanis 2003.
2// Distributed under the Boost Software License, Version 1.0. (See accompanying
3// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt.)
4
5// See http://www.boost.org/libs/iostreams for documentation.
6
7#ifndef BOOST_IOSTREAMS_PIPABLE_HPP_INCLUDED
8#define BOOST_IOSTREAMS_PIPABLE_HPP_INCLUDED
9
10#if defined(_MSC_VER) && (_MSC_VER >= 1020)
11# pragma once
12#endif
13
14#include <boost/config.hpp> // BOOST_MSVC.
15#include <boost/detail/workaround.hpp>           
16#include <boost/iostreams/detail/template_params.hpp>
17#include <boost/iostreams/traits.hpp>
18#include <boost/mpl/bool.hpp>
19#include <boost/preprocessor/punctuation/comma_if.hpp>
20#include <boost/preprocessor/repetition/enum_params.hpp>
21#include <boost/static_assert.hpp>
22#if BOOST_WORKAROUND(BOOST_MSVC, < 1300)
23# include <boost/type_traits/is_base_and_derived.hpp>
24#endif
25
26#define BOOST_IOSTREAMS_PIPABLE(filter, arity) \
27    template< BOOST_PP_ENUM_PARAMS(arity, typename T) \
28              BOOST_PP_COMMA_IF(arity) typename Component> \
29    ::boost::iostreams::pipeline< \
30        ::boost::iostreams::detail::pipeline_segment< \
31            filter BOOST_IOSTREAMS_TEMPLATE_ARGS(arity, T) \
32        >, \
33        Component \
34    > operator|( const filter BOOST_IOSTREAMS_TEMPLATE_ARGS(arity, T)& f, \
35                 const Component& c ) \
36    { \
37        typedef ::boost::iostreams::detail::pipeline_segment< \
38                    filter BOOST_IOSTREAMS_TEMPLATE_ARGS(arity, T) \
39                > segment; \
40        return ::boost::iostreams::pipeline<segment, Component> \
41                   (segment(f), c); \
42    } \
43    /**/
44
45namespace boost { namespace iostreams {
46
47template<typename Pipeline, typename Component>
48struct pipeline;
49   
50namespace detail {
51
52#if BOOST_WORKAROUND(BOOST_MSVC, <= 1300)
53    struct pipeline_base { };
54
55    template<typename T>
56    struct is_pipeline
57        : is_base_and_derived<pipeline_base, T>
58        { };
59#endif
60#if BOOST_WORKAROUND(__BORLANDC__, < 0x600)
61    template<typename T>
62    struct is_pipeline : mpl::false_ { };
63
64    template<typename Pipeline, typename Component>
65    struct is_pipeline< pipeline<Pipeline, Component> > : mpl::true_ { };
66#endif
67
68template<typename Component>
69class pipeline_segment
70#if BOOST_WORKAROUND(BOOST_MSVC, <= 1300)
71    : pipeline_base
72#endif
73{
74public:
75    pipeline_segment(const Component& component)
76        : component_(component)
77        { }
78    template<typename Fn>
79    void for_each(Fn fn) const { fn(component_); }
80    template<typename Chain>
81    void push(Chain& chn) const { chn.push(component_); }
82private:
83    const Component& component_;
84};
85
86} // End namespace detail.
87                   
88//------------------Definition of Pipeline------------------------------------//
89
90template<typename Pipeline, typename Component>
91struct pipeline : Pipeline {
92    typedef Pipeline   pipeline_type;
93    typedef Component  component_type;
94    pipeline(const Pipeline& p, const Component& component)
95        : Pipeline(p), component_(component)
96        { }
97    template<typename Fn>
98    void for_each(Fn fn) const
99    {
100        Pipeline::for_each(fn);
101        fn(component_);
102    }
103    template<typename Chain>
104    void push(Chain& chn) const
105    {
106        Pipeline::push(chn);
107        chn.push(component_);
108    }
109    const Pipeline& tail() const { return *this; }
110    const Component& head() const { return component_; }
111private:
112    const Component& component_;
113};
114
115template<typename Pipeline, typename Filter, typename Component>
116pipeline<pipeline<Pipeline, Filter>, Component>
117operator|(const pipeline<Pipeline, Filter>& p, const Component& cmp)
118{
119    BOOST_STATIC_ASSERT(is_filter<Filter>::value);
120    return pipeline<pipeline<Pipeline, Filter>, Component>(p, cmp);
121}
122
123} } // End namespaces iostreams, boost.
124
125#endif // #ifndef BOOST_IOSTREAMS_PIPABLE_HPP_INCLUDED
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