[29] | 1 | <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> |
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| 2 | <HTML> |
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| 3 | <HEAD> |
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| 4 | <TITLE>File Wrappers</TITLE> |
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| 5 | <LINK REL="stylesheet" HREF="../../../../boost.css"> |
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| 6 | <LINK REL="stylesheet" HREF="../theme/iostreams.css"> |
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| 7 | </HEAD> |
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| 8 | <BODY> |
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| 9 | |
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| 10 | <!-- Begin Banner --> |
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| 11 | |
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| 12 | <H1 CLASS="title">File Wrappers</H1> |
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| 13 | <HR CLASS="banner"> |
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| 14 | |
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| 15 | <!-- End Banner --> |
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| 16 | |
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| 17 | <DL class="page-index"> |
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| 18 | <DT><A href="#overview">Overview</A></DT> |
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| 19 | <DT><A href="#headers">Headers</A></DT> |
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| 20 | <DT><A href="#reference">Reference</A> |
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| 21 | <UL> |
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| 22 | <LI CLASS="square"><A href="#file_source">Class template <CODE>basic_file_source</CODE></A></LI> |
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| 23 | <LI CLASS="square"><A href="#file_sink">Class template <CODE>basic_file_sink</CODE></A></LI> |
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| 24 | <LI CLASS="square"><A href="#file">Class template <CODE>basic_file</CODE></A></LI> |
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| 25 | </UL> |
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| 26 | </DT> |
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| 27 | </DL> |
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| 28 | |
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| 29 | <HR> |
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| 30 | |
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| 31 | <A NAME="overview"></A> |
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| 32 | <H2>Overview</H2> |
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| 33 | |
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| 34 | <P> |
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| 35 | The class templates <CODE>basic_file_source</CODE>, <CODE>basic_file_sink</CODE> and <CODE>basic_file</CODE> are wrappers for <CODE>std::basic_filebuf</CODE> which are <A HREF="http://www.boost.org/libs/utility/CopyConstructible.html" TARGET="_top">CopyConstructible</A> and <A HREF="http://www.boost.org/libs/utility/Assignable.html">Assignable</A>. They are useful whenever one wants to access a file without managing the lifetime of a standard file stream or stream buffer. This is because when a stream or stream buffer is added to a <A HREF="filtering_streambuf.html"><CODE>filtering_streambuf</CODE></A> or <A HREF="filtering_stream.html"><CODE>filtering_stream</CODE></A> it is stored as a reference which must remain valid until that stream or stream buffer is removed from the chain. |
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| 36 | </P> |
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| 37 | <P> |
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| 38 | The most common specializations are accessible via the typedefs <CODE>file_source</CODE>, <CODE>file_sink</CODE>, <CODE>file</CODE>, <CODE>wfile_source</CODE>, <CODE>wfile_sink</CODE> and <CODE>wfile</CODE>. |
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| 39 | </P> |
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| 40 | |
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| 41 | <A NAME="headers"></A> |
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| 42 | <H2>Headers</H2> |
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| 43 | |
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| 44 | <DL class="page-index"> |
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| 45 | <DT><A CLASS="header" HREF="../../../../boost/iostreams/device/file.hpp"><CODE><boost/iostreams/device/file.hpp></CODE></A></DT> |
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| 46 | </DL> |
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| 47 | |
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| 48 | <A NAME="reference"></A> |
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| 49 | <H2>Reference</H2> |
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| 50 | |
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| 51 | <A NAME="file_source"></A> |
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| 52 | <H3>Class template <CODE>basic_file_source</CODE></H3> |
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| 53 | |
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| 54 | <H4>Description</H4> |
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| 55 | |
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| 56 | <P> |
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| 57 | <A HREF="http://www.boost.org/libs/utility/CopyConstructible.html" TARGET="_top">CopyConstructible</A> and <A HREF="http://www.boost.org/libs/utility/Assignable.html">Assignable</A> wrapper for a <CODE>std::basic_filebuf</CODE> opened in read-only mode. |
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| 58 | <P> |
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| 59 | |
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| 60 | <A NAME="file_source_synopsis"></A> |
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| 61 | <H4>Synopsis</H4> |
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| 62 | |
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| 63 | <PRE CLASS="broken_ie"><SPAN CLASS="keyword">namespace</SPAN> boost { <SPAN CLASS="keyword">namespace</SPAN> iostreams { |
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| 64 | |
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| 65 | <SPAN CLASS="keyword">template</SPAN><<SPAN CLASS="keyword">typename</SPAN> <A CLASS="documented" HREF="#basic_file_source_params">Ch</A>> |
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| 66 | <SPAN CLASS="keyword">class</SPAN> <A CLASS="documented" HREF="#basic_file_source_params">basic_file_source</A> { |
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| 67 | <SPAN CLASS="keyword">public</SPAN>: |
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| 68 | <SPAN CLASS="keyword">typedef</SPAN> Ch char_type; |
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| 69 | <SPAN CLASS="keyword">typedef</SPAN> <SPAN CLASS="omitted">implementation-defined</SPAN> category; |
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| 70 | <A CLASS="documented" HREF="#basic_file_source_constructor">basic_file_source</A>( <SPAN CLASS="keyword">const</SPAN> std::string& path, |
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| 71 | std::ios_base::openmode mode = |
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| 72 | std::ios_base::in ); |
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| 73 | <SPAN CLASS="keyword">bool</SPAN> <A CLASS="documented" HREF="#basic_file_source_is_open">is_open</A>() <SPAN CLASS="keyword">const</SPAN>; |
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| 74 | <SPAN CLASS="omitted">...</SPAN> |
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| 75 | }; |
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| 76 | |
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| 77 | <SPAN CLASS="keyword">typedef</SPAN> basic_file_source<<SPAN CLASS="keyword">char</SPAN>> <SPAN CLASS="defined">file_source</SPAN>; |
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| 78 | <SPAN CLASS="keyword">typedef</SPAN> basic_file_source<<SPAN CLASS="keyword">wchar_t</SPAN>> <SPAN CLASS="defined">wfile_source</SPAN>; |
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| 79 | |
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| 80 | } } <SPAN CLASS='comment'>// End namespace boost::iostreams</SPAN></PRE> |
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| 81 | |
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| 82 | <A NAME="basic_file_source_params"></A> |
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| 83 | <H4>Template parameters</H4> |
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| 84 | |
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| 85 | <TABLE STYLE="margin-left:2em"> |
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| 86 | <TR> |
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| 87 | <TD><I>Ch</I></TD><TD VALIGN="top">-</TD> |
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| 88 | <TD>The character type.</TD></TR> |
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| 89 | <TR> |
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| 90 | </TABLE> |
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| 91 | |
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| 92 | <A NAME="basic_file_source_constructor"></A> |
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| 93 | <H4><CODE>basic_file_source::basic_file_source</CODE></H4> |
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| 94 | |
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| 95 | <PRE CLASS="broken_ie"> basic_file_source( <SPAN CLASS="keyword">const</SPAN> std::string& path, |
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| 96 | std::ios_base::openmode mode );</PRE> |
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| 97 | |
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| 98 | <P> |
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| 99 | Constructs a <CODE>basic_file_source</CODE> which wraps a <CODE>std::basic_filebuf</CODE> <CODE>buf</CODE> opened as follows: |
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| 100 | <PRE CLASS="broken_ie"> mode |= std::ios_base::in; |
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| 101 | mode &= ~std::ios_base::out; |
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| 102 | buf.open(path.c_str(), mode);</PRE> |
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| 103 | </P> |
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| 104 | |
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| 105 | <A NAME="basic_file_source_is_open"></A> |
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| 106 | <H4><CODE>basic_file_source::is_open</CODE></H4> |
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| 107 | |
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| 108 | <PRE CLASS="broken_ie"> <SPAN CLASS="keyword">bool</SPAN> is_open() <SPAN CLASS="keyword">const</SPAN>;</PRE> |
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| 109 | |
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| 110 | <P>Returns <CODE>true</CODE> if the underlying instance of <CODE>basic_filebuf</CODE> was opened successfully.</P> |
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| 111 | |
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| 112 | <A NAME="file_sink"></A> |
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| 113 | <H3>Class template <CODE>basic_file_sink</CODE></H3> |
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| 114 | |
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| 115 | <H4>Description</H4> |
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| 116 | |
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| 117 | <P> |
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| 118 | <A HREF="http://www.boost.org/libs/utility/CopyConstructible.html" TARGET="_top">CopyConstructible</A> and <A HREF="http://www.boost.org/libs/utility/Assignable.html">Assignable</A> wrapper for a <CODE>std::basic_filebuf</CODE> opened in write-only mode. |
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| 119 | <P> |
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| 120 | |
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| 121 | <A NAME="file_sink_synopsis"></A> |
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| 122 | <H4>Synopsis</H4> |
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| 123 | |
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| 124 | <PRE CLASS="broken_ie"><SPAN CLASS="keyword">namespace</SPAN> boost { <SPAN CLASS="keyword">namespace</SPAN> iostreams { |
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| 125 | |
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| 126 | <SPAN CLASS="keyword">template</SPAN><<SPAN CLASS="keyword">typename</SPAN> <A CLASS="documented" HREF="#basic_file_sink_params">Ch</A>> |
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| 127 | <SPAN CLASS="keyword">class</SPAN> <A CLASS="documented" HREF="#basic_file_sink_params">basic_file_sink</A> { |
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| 128 | <SPAN CLASS="keyword">public</SPAN>: |
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| 129 | <SPAN CLASS="keyword">typedef</SPAN> Ch char_type; |
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| 130 | <SPAN CLASS="keyword">typedef</SPAN> <SPAN CLASS="omitted">implementation-defined</SPAN> category; |
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| 131 | <A CLASS="documented" HREF="#basic_file_sink_constructor">basic_file_sink</A>( <SPAN CLASS="keyword">const</SPAN> std::string& path, |
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| 132 | std::ios_base::openmode mode = |
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| 133 | std::ios_base::out ); |
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| 134 | <SPAN CLASS="keyword">bool</SPAN> <A CLASS="documented" HREF="#basic_file_sink_is_open">is_open</A>() <SPAN CLASS="keyword">const</SPAN>; |
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| 135 | <SPAN CLASS="omitted">...</SPAN> |
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| 136 | }; |
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| 137 | |
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| 138 | <SPAN CLASS="keyword">typedef</SPAN> basic_file_sink<<SPAN CLASS="keyword">char</SPAN>> <SPAN CLASS="defined">file_sink</SPAN>; |
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| 139 | <SPAN CLASS="keyword">typedef</SPAN> basic_file_sink<<SPAN CLASS="keyword">wchar_t</SPAN>> <SPAN CLASS="defined">wfile_sink</SPAN>; |
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| 140 | |
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| 141 | } } <SPAN CLASS='comment'>// End namespace boost::iostreams</SPAN></PRE> |
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| 142 | |
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| 143 | <A NAME="basic_file_sink_params"></A> |
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| 144 | <H4>Template parameters</H4> |
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| 145 | |
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| 146 | <TABLE STYLE="margin-left:2em"> |
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| 147 | <TR> |
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| 148 | <TD><I>Ch</I></TD><TD VALIGN="top">-</TD> |
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| 149 | <TD>The character type.</TD></TR> |
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| 150 | <TR> |
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| 151 | </TABLE> |
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| 152 | |
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| 153 | <A NAME="basic_file_sink_constructor"></A> |
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| 154 | <H4><CODE>basic_file_sink::basic_file_sink</CODE></H4> |
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| 155 | |
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| 156 | <PRE CLASS="broken_ie"> basic_file_sink( <SPAN CLASS="keyword">const</SPAN> std::string& path, |
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| 157 | std::ios_base::openmode mode );</PRE> |
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| 158 | |
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| 159 | <P> |
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| 160 | Constructs a <CODE>basic_file_sink</CODE> which wraps a <CODE>std::basic_filebuf</CODE> <CODE>buf</CODE> opened as follows: |
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| 161 | <PRE CLASS="broken_ie"> mode |= std::ios_base::out; |
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| 162 | mode &= ~std::ios_base::in; |
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| 163 | buf.open(path.c_str(), mode);</PRE> |
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| 164 | </P> |
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| 165 | |
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| 166 | <A NAME="basic_file_sink_is_open"></A> |
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| 167 | <H4><CODE>basic_file_sink::is_open</CODE></H4> |
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| 168 | |
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| 169 | <PRE CLASS="broken_ie"> <SPAN CLASS="keyword">bool</SPAN> is_open() <SPAN CLASS="keyword">const</SPAN>;</PRE> |
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| 170 | |
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| 171 | <P>Returns <CODE>true</CODE> if the underlying instance of <CODE>basic_filebuf</CODE> was opened successfully.</P> |
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| 172 | |
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| 173 | <A NAME="file"></A> |
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| 174 | <H3>Class template <CODE>basic_file</CODE></H3> |
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| 175 | |
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| 176 | <H4>Description</H4> |
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| 177 | |
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| 178 | <P><A HREF="http://www.boost.org/libs/utility/CopyConstructible.html" TARGET="_top">CopyConstructible</A> and <A HREF="http://www.boost.org/libs/utility/Assignable.html">Assignable</A> wrapper for a <CODE>std::basic_filebuf</CODE> opened in read-write mode by default. |
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| 179 | |
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| 180 | <A NAME="file_synopsis"></A> |
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| 181 | <H4>Synopsis</H4> |
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| 182 | |
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| 183 | <PRE CLASS="broken_ie"><SPAN CLASS="keyword">namespace</SPAN> boost { <SPAN CLASS="keyword">namespace</SPAN> iostreams { |
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| 184 | |
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| 185 | <SPAN CLASS="keyword">template</SPAN><<SPAN CLASS="keyword">typename</SPAN> <A CLASS="documented" HREF="#basic_file_params">Ch</A>> |
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| 186 | <SPAN CLASS="keyword">class</SPAN> <A CLASS="documented" HREF="#basic_file_params">basic_file</A> { |
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| 187 | <SPAN CLASS="keyword">public</SPAN>: |
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| 188 | <SPAN CLASS="keyword">typedef</SPAN> Ch char_type; |
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| 189 | <SPAN CLASS="keyword">typedef</SPAN> <SPAN CLASS="omitted">implementation-defined</SPAN> category; |
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| 190 | <A CLASS="documented" HREF="#basic_file_constructor">basic_file</A>( <SPAN CLASS="keyword">const</SPAN> std::string& path, |
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| 191 | std::ios_base::openmode mode = |
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| 192 | std::ios_base::in | std::ios_base::out ); |
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| 193 | <SPAN CLASS="keyword">bool</SPAN> <A CLASS="documented" HREF="#basic_file_is_open">is_open</A>() <SPAN CLASS="keyword">const</SPAN>; |
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| 194 | <SPAN CLASS="omitted">...</SPAN> |
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| 195 | }; |
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| 196 | |
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| 197 | <SPAN CLASS="keyword">typedef</SPAN> basic_file<<SPAN CLASS="keyword">char</SPAN>> <SPAN CLASS="defined">file</SPAN>; |
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| 198 | <SPAN CLASS="keyword">typedef</SPAN> basic_file<<SPAN CLASS="keyword">wchar_t</SPAN>> <SPAN CLASS="defined">wfile</SPAN>; |
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| 199 | |
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| 200 | } } <SPAN CLASS='comment'>// End namespace boost::iostreams</SPAN></PRE> |
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| 201 | |
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| 202 | <A NAME="basic_file_params"></A> |
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| 203 | <H4>Template parameters</H4> |
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| 204 | |
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| 205 | <TABLE STYLE="margin-left:2em"> |
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| 206 | <TR> |
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| 207 | <TD><I>Ch</I></TD><TD VALIGN="top">-</TD> |
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| 208 | <TD>The character type.</TD></TR> |
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| 209 | <TR> |
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| 210 | </TABLE> |
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| 211 | |
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| 212 | <A NAME="basic_file_constructor"></A> |
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| 213 | <H4><CODE>basic_file_::basic_file</CODE></H4> |
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| 214 | |
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| 215 | <PRE CLASS="broken_ie"> basic_file( <SPAN CLASS="keyword">const</SPAN> std::string& path, |
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| 216 | std::ios_base::openmode mode );</PRE> |
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| 217 | |
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| 218 | <P> |
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| 219 | Constructs a <CODE>basic_file</CODE> which wraps a <CODE>std::basic_filebuf</CODE> <CODE>buf</CODE> opened as follows: |
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| 220 | <PRE CLASS="broken_ie"> mode |= std::ios_base::in | std::ios_base::out; |
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| 221 | buf.open(path.c_str(), mode);</PRE> |
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| 222 | </P> |
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| 223 | |
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| 224 | <A NAME="basic_file_is_open"></A> |
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| 225 | <H4><CODE>basic_file::is_open</CODE></H4> |
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| 226 | |
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| 227 | <PRE CLASS="broken_ie"> <SPAN CLASS="keyword">bool</SPAN> is_open() <SPAN CLASS="keyword">const</SPAN>;</PRE> |
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| 228 | |
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| 229 | <P>Returns <CODE>true</CODE> if the underlying instance of <CODE>basic_filebuf</CODE> was opened successfully.</P> |
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| 230 | |
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| 231 | <!-- Begin Footer --> |
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| 232 | |
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| 233 | <HR> |
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| 234 | <P CLASS="copyright">Revised |
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| 235 | <!--webbot bot="Timestamp" S-Type="EDITED" S-Format="%d %B, %Y" startspan --> |
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| 236 | 20 May, 2004 |
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| 237 | <!--webbot bot="Timestamp" endspan i-checksum="38504" --> |
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| 238 | </P> |
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| 239 | |
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| 240 | <P CLASS="copyright">© Copyright <A HREF="http://www.kangaroologic.com" TARGET="_top">Jonathan Turkanis</A>, 2004</P> |
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| 241 | <P CLASS="copyright"> |
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| 242 | Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at <A HREF="http://www.boost.org/LICENSE_1_0.txt">http://www.boost.org/LICENSE_1_0.txt</A>) |
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| 243 | </P> |
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| 244 | |
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| 245 | <!-- End Footer --> |
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| 246 | |
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| 247 | </BODY> |
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