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Add binary_stream_example.cpp. Improve docs.

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git-svn-id: http://svn.boost.org/svn/boost/sandbox/endian@71463 b8fc166d-592f-0410-95f2-cb63ce0dd405
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bemandawes
2011-04-24 10:59:20 +00:00
parent 793e21594c
commit c3d5f2e2f8
4 changed files with 148 additions and 14 deletions
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libs/integer/doc/binary_stream.html
+28 -14
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@@ -11,14 +11,14 @@
<body>
<h1>Proposal for Enhanced Binary Stream I/O</h1>
<h1>Proposal for Binary Stream I/O</h1>
<h2>Introduction</h2>
<p>The C++ standard library's stream I/O facilities are type-safe and very
convenient for performing formatted (i.e. human readable) I/O, but offer only
rudimentary and not very type-safe operations for performing binary I/O.&nbsp;
convenient for performing formatted (i.e. human readable) I/O. But they offer only
rudimentary and not very type-safe operations for performing unformatted binary I/O.&nbsp;
Although formatted I/O is often preferable, some applications need the speed and
storage efficiency of binary I/O or need to interoperate with third-party
applications that require binary file or network data formats.</p>
storage efficiency of unformatted binary I/O or need to interoperate with third-party
applications that require unformatted binary file or network data formats.</p>
<p>Standard library streams can be opened with filemode <code>
std::ios_base::binary</code>, so binary I/O is possible. But the only
unformatted I/O functions available are <code>get()</code>, <code>put()</code>,
@@ -33,9 +33,9 @@ have in mind is for the simple case where the application that reads data knows
the data types, so this is not as complicated as the general marshalling
situation.</p>
</blockquote>
<p>This proposal provides a simple solution that works will standard library
input and output streams. The one caveat is that they should be open with
filemode <code>std::ios_base::binary</code>.</p>
<p>This proposal provides a simple solution that works with standard library
input and output streams. The one caveat is that the stream must be opened with filemode <code>std::ios_base::binary</code>
to avoid certain data values being treated as line endings.</p>
<h2>Synopsis</h2>
<div dir="ltr">
<pre>namespace boost
@@ -62,19 +62,33 @@ are implementation supplied types.</p>
<blockquote>
<pre>int main()
{
int i = 0x41424344;
std::cout &lt;&lt; std::hex &lt;&lt; i &lt;&lt; &quot; &quot; &lt;&lt; bin(i) &lt;&lt; '\n';
fstream f(&quot;binary_stream_example.dat&quot;,
std::ios_base::trunc | std::ios_base::in | std::ios_base::out | std::ios_base::binary);
int32_t x = 0x01020304;
int32_t y = 0;
f &lt;&lt; bin(x);
f.seekg(0);
f &gt;&gt; bin(y);
BOOST_ASSERT(x == y);
return 0;
}</pre>
</blockquote>
<p>On a little-endian machine, the output is:</p>
<p>The file produced with be four bytes in length. On a big-endian machine, the
contents in hexadecimal are:</p>
<blockquote>
<pre>41424344 DCBA</pre>
<pre>01020304</pre>
</blockquote>
<p>On a little-endian machine, the contents in hexadecimal are:</p>
<blockquote>
<pre>04030201</pre>
</blockquote>
<p>&nbsp;</p>
<hr>
<p>Last revised:
<!--webbot bot="Timestamp" s-type="EDITED" s-format="%d %B, %Y" startspan -->22 April, 2011<!--webbot bot="Timestamp" endspan i-checksum="29826" --></p>
<!--webbot bot="Timestamp" s-type="EDITED" s-format="%d %B, %Y" startspan -->24 April, 2011<!--webbot bot="Timestamp" endspan i-checksum="29830" --></p>
<p>© Copyright Beman Dawes, 2009, 2011</p>
<p>Distributed under the Boost Software License, Version 1.0. See
<a href="http://www.boost.org/LICENSE_1_0.txt">www.boost.org/ LICENSE_1_0.txt</a></p>