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A fresh approach for binary_stream.hpp

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git-svn-id: http://svn.boost.org/svn/boost/sandbox/endian@71421 b8fc166d-592f-0410-95f2-cb63ce0dd405
This commit is contained in:
bemandawes
2011-04-22 20:34:30 +00:00
parent 2165d7908d
commit 793e21594c
3 changed files with 193 additions and 186 deletions
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157
boost/binary_stream.hpp
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@@ -1,6 +1,6 @@
// boost/binary_stream.hpp ----------------------------------------------------------// // boost/binary_stream.hpp ----------------------------------------------------------//
// Copyright Beman Dawes 2009 // Copyright Beman Dawes 2009, 2011
// Distributed under the Boost Software License, Version 1.0. // Distributed under the Boost Software License, Version 1.0.
// See http://www.boost.org/LICENSE_1_0.txt // See http://www.boost.org/LICENSE_1_0.txt
@@ -20,7 +20,7 @@
# include <cwchar> // for wcslen # include <cwchar> // for wcslen
#endif #endif
// unformatted binary (as opposed to formatted character-set) input and output // unformatted binary (as opposed to formatted character) input and output
// Caution: Use only on streams opened with filemode std::ios_base::binary. Thus // Caution: Use only on streams opened with filemode std::ios_base::binary. Thus
// unformatted binary I/O should not be with the standard streams (cout, cin, etc.) // unformatted binary I/O should not be with the standard streams (cout, cin, etc.)
@@ -28,127 +28,54 @@
// results, such as insertion of unwanted characters or premature end-of-file. // results, such as insertion of unwanted characters or premature end-of-file.
// For example, on Windows 0x0D would become 0x0D, 0x0A. // For example, on Windows 0x0D would become 0x0D, 0x0A.
// Caution: When mixing formatted (i.e. operator << or >>) and unformatted (i.e.
// operator <= or >=) be aware that << and >> take precedence over <= and >=. Use
// parentheses to force correct order of evaluation. For example:
//
// my_stream << foo <= bar; // no parentheses needed
// (my_stream <= foo) << bar; // parentheses required
// This implementation uses reinterpret_cast<>() when needed to convert one pointer
// type to another. See 5.2.10 [expr.reinterpret.cast], Reinterpret cast, para 7.
namespace boost namespace boost
{ {
// built-in types ------------------------------------------------------------------// namespace detail
{
template <class T>
struct const_binary_data
{
const char* ptr;
explicit const_binary_data(const T& x) : ptr(reinterpret_cast<const char*>(&x)) {}
};
template <class T>
struct binary_data
{
char* ptr;
explicit binary_data(T& x) : ptr(reinterpret_cast<char*>(&x)) {}
};
}
// omission of bool and void* is deliberate; any semantics would be questionable template <class T>
inline detail::const_binary_data<T> bin(const T& x)
{
return detail::const_binary_data<T>(x);
}
inline std::ostream& operator<=(std::ostream& os, short v) template <class T>
{ return os.write( reinterpret_cast<const char*>(&v), sizeof(v) ); } inline detail::binary_data<T> bin(T& x)
inline std::istream& operator>=(std::istream& is, short& v) {
{ return is.read( reinterpret_cast<char*>(&v), sizeof(v) ); } return detail::binary_data<T>(x);
}
inline std::ostream& operator<=(std::ostream& os, unsigned short v) template <class T>
{ return os.write( reinterpret_cast<const char*>(&v), sizeof(v) ); } inline std::ostream& operator<<(std::ostream& os, detail::const_binary_data<T> x)
inline std::istream& operator>=(std::istream& is, unsigned short& v) {
{ return is.read( reinterpret_cast<char*>(&v), sizeof(v) ); } return os.write(x.ptr, sizeof(T));
}
inline std::ostream& operator<=(std::ostream& os, int v) template <class T>
{ return os.write( reinterpret_cast<const char*>(&v), sizeof(v) ); } inline std::ostream& operator<<(std::ostream& os, detail::binary_data<T> x)
inline std::istream& operator>=(std::istream& is, int& v) {
{ return is.read( reinterpret_cast<char*>(&v), sizeof(v) ); } return os.write(x.ptr, sizeof(T));
}
inline std::ostream& operator<=(std::ostream& os, unsigned int v) template <class T>
{ return os.write( reinterpret_cast<const char*>(&v), sizeof(v) ); } inline std::istream& operator>>(std::istream& is, detail::binary_data<T> x)
inline std::istream& operator>=(std::istream& is, unsigned int& v) {
{ return is.read( reinterpret_cast<char*>(&v), sizeof(v) ); } return is.read(x.ptr, sizeof(T));
}
inline std::ostream& operator<=(std::ostream& os, long v)
{ return os.write( reinterpret_cast<const char*>(&v), sizeof(v) ); }
inline std::istream& operator>=(std::istream& is, long& v)
{ return is.read( reinterpret_cast<char*>(&v), sizeof(v) ); }
inline std::ostream& operator<=(std::ostream& os, unsigned long v)
{ return os.write( reinterpret_cast<const char*>(&v), sizeof(v) ); }
inline std::istream& operator>=(std::istream& is, unsigned long& v)
{ return is.read( reinterpret_cast<char*>(&v), sizeof(v) ); }
inline std::ostream& operator<=(std::ostream& os, long long v)
{ return os.write( reinterpret_cast<const char*>(&v), sizeof(v) ); }
inline std::istream& operator>=(std::istream& is, long long& v)
{ return is.read( reinterpret_cast<char*>(&v), sizeof(v) ); }
inline std::ostream& operator<=(std::ostream& os, unsigned long long v)
{ return os.write( reinterpret_cast<const char*>(&v), sizeof(v) ); }
inline std::istream& operator>=(std::istream& is, unsigned long long& v)
{ return is.read( reinterpret_cast<char*>(&v), sizeof(v) ); }
inline std::ostream& operator<=(std::ostream& os, float v)
{ return os.write( reinterpret_cast<const char*>(&v), sizeof(v) ); }
inline std::istream& operator>=(std::istream& is, float& v)
{ return is.read( reinterpret_cast<char*>(&v), sizeof(v) ); }
inline std::ostream& operator<=(std::ostream& os, double v)
{ return os.write( reinterpret_cast<const char*>(&v), sizeof(v) ); }
inline std::istream& operator>=(std::istream& is, double& v)
{ return is.read( reinterpret_cast<char*>(&v), sizeof(v) ); }
inline std::ostream& operator<=(std::ostream& os, long double v)
{ return os.write( reinterpret_cast<const char*>(&v), sizeof(v) ); }
inline std::istream& operator>=(std::istream& is, long double& v)
{ return is.read( reinterpret_cast<char*>(&v), sizeof(v) ); }
inline std::ostream& operator<=(std::ostream& os, char c)
{ return os.put( c ); }
inline std::istream& operator>=(std::istream& is, char& c)
{ return is.get( c ); }
inline std::ostream& operator<=(std::ostream& os, signed char c)
{ return os.put( c ); }
inline std::istream& operator>=(std::istream& is, signed char& c)
{ return is.get( reinterpret_cast<char&>(c) ); }
inline std::ostream& operator<=(std::ostream& os, unsigned char c)
{ return os.put( c ); }
inline std::istream& operator>=(std::istream& is, unsigned char& c)
{ return is.get( reinterpret_cast<char&>(c) ); }
inline std::ostream& operator<=(std::ostream& os, wchar_t v)
{ return os.write( reinterpret_cast<const char*>(&v), sizeof(v) ); }
inline std::istream& operator>=(std::istream& is, wchar_t& v)
{ return is.read( reinterpret_cast<char*>(&v), sizeof(v) ); }
// strings -------------------------------------------------------------------------//
inline std::ostream& operator<=(std::ostream& os, const char* p)
{ return os.write( p, std::strlen(p)+1 ); }
inline std::ostream& operator<=(std::ostream& os, const signed char* p)
{ return os.write( reinterpret_cast<const char*>(p), std::strlen(reinterpret_cast<const char*>(p))+1 ); }
inline std::ostream& operator<=(std::ostream& os, const unsigned char* p)
{ return os.write( reinterpret_cast<const char*>(p), std::strlen(reinterpret_cast<const char*>(p))+1 ); }
#ifndef BOOST_NO_CWCHAR
inline std::ostream& operator<=(std::ostream& os, const wchar_t* p)
{ return os.write( reinterpret_cast<const char*>(p), (std::wcslen(p)+1)*sizeof(wchar_t) ); }
#endif
// Caution: note the asymmetry between output and input; a string with embedded
// nulls will be output with the embedded nulls, but input will stop at the first null.
// So it probably isn't a good idea to use these functions for strings with nulls.
inline std::ostream& operator<=(std::ostream& os, const std::string& s)
{ return os.write( s.c_str(), s.size()+1 ); }
inline std::istream& operator>=(std::istream& is, std::string& s)
{ return getline(is, s, '\0'); }
#ifndef BOOST_NO_STD_WSTRING
inline std::ostream& operator<=(std::ostream& os, const std::wstring& s)
{ return os.write( reinterpret_cast<const char*>(s.c_str()), (s.size()+1)*sizeof(wchar_t) ); }
// TODO: provide input function
#endif
} // namespace boost } // namespace boost

89
libs/integer/doc/binary_stream.html Normal file
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@@ -0,0 +1,89 @@
<html>
<head>
<meta http-equiv="Content-Language" content="en-us">
<meta name="GENERATOR" content="Microsoft FrontPage 5.0">
<meta name="ProgId" content="FrontPage.Editor.Document">
<meta http-equiv="Content-Type" content="text/html; charset=windows-1252">
<title>Binary Stream I/O</title>
<link rel="stylesheet" type="text/css" href="../../../doc/html/minimal.css">
</head>
<body>
<h1>Proposal for Enhanced 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;
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>
<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>,
<code>read()</code>, and <code>write()</code>. These operate only on <code>char</code>
or array of <code>char</code> (with length explicitly specified), so require the
user to write casts, are hard to use, and are error prone.</p>
<p>There have been many requests on Boost and various C++ newsgroups for
unformatted binary I/O. For example, in 2003 Neal Becker wrote:</p>
<blockquote>
<p>I wonder if anyone has code for implementing unformatted I/O?&nbsp; What I
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>
<h2>Synopsis</h2>
<div dir="ltr">
<pre>namespace boost
{
template &lt;class T&gt;
<i>unspecified-type-1&lt;T&gt;</i> bin(const T&amp; x);
template &lt;class T&gt;
<i>unspecified-type-2&lt;T&gt;</i> bin(T&amp; x);
template &lt;class T&gt;
std::ostream&amp; operator&lt;&lt;(std::ostream&amp; os, <i>unspecified-type-1&lt;T&gt;</i> x);
template &lt;class T&gt;
std::ostream&amp; operator&lt;&lt;(std::ostream&amp; os, <i>unspecified-type-2&lt;T&gt;</i> x);
template &lt;class T&gt;
std::istream&amp; operator&gt;&gt;(std::istream&amp; is, <i>unspecified-type-2&lt;T&gt;</i> x);
}</pre>
</div>
<p><i><code>unspecified-type-1</code></i> and <i><code>unspecified-type-2</code></i>
are implementation supplied types.</p>
<h2>Example</h2>
<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';
return 0;
}</pre>
</blockquote>
<p>On a little-endian machine, the output is:</p>
<blockquote>
<pre>41424344 DCBA</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>
<p><EFBFBD> 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>
<p>&nbsp;</p>
<p>&nbsp;</p>
<p>&nbsp;</p>
<p>&nbsp;</p>
</body>
</html>

133
libs/integer/test/binary_stream_test.cpp
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@@ -9,113 +9,104 @@
#include <string> #include <string>
#include <iostream> #include <iostream>
#include <sstream> #include <sstream>
#include <boost/detail/lightweight_test.hpp>
using namespace boost; using namespace boost;
using namespace std; using namespace std;
namespace
{
int errors = 0;
void verify( bool x, const char * file, int line )
{
if ( x ) return;
++errors;
cout << file << "(" << line << ") : error: predicate is false\n" << endl;
}
}
#define BOOST_VERIFY(predicate) verify( predicate, __FILE__, __LINE__ )
int main() int main()
{ {
std::stringstream ss( std::ios_base::in | std::ios_base::out | std::ios_base::binary ); std::stringstream ss( std::ios_base::in | std::ios_base::out | std::ios_base::binary );
short short_1(0x0102), short_2; short short_1(0x0102), short_2;
ss <= short_1; ss.clear();
ss >= short_2; ss << bin(short_1);
BOOST_VERIFY( short_1 == short_2 ); ss >> bin(short_2);
BOOST_TEST( short_1 == short_2 );
unsigned short ushort_1(0x0102), ushort_2; unsigned short ushort_1(0x0102), ushort_2;
ss <= ushort_1; ss.clear();
ss >= ushort_2; ss << bin(ushort_1);
BOOST_VERIFY( ushort_1 == ushort_2 ); ss >> bin(ushort_2);
BOOST_TEST( ushort_1 == ushort_2 );
int int_1(0x01020304), int_2; int int_1(0x01020304), int_2;
ss <= int_1; ss.clear();
ss >= int_2; ss << bin(int_1);
BOOST_VERIFY( int_1 == int_2 ); ss >> bin(int_2);
BOOST_TEST( int_1 == int_2 );
unsigned int uint_1(0x01020304), uint_2; unsigned int uint_1(0x01020304), uint_2;
ss <= uint_1; ss.clear();
ss >= uint_2; ss << bin(uint_1);
BOOST_VERIFY( uint_1 == uint_2 ); ss >> bin(uint_2);
BOOST_TEST( uint_1 == uint_2 );
long long_1(0x01020304L), long_2; long long_1(0x01020304L), long_2;
ss <= long_1; ss.clear();
ss >= long_2; ss << bin(long_1);
BOOST_VERIFY( long_1 == long_2 ); ss >> bin(long_2);
BOOST_TEST( long_1 == long_2 );
unsigned long ulong_1(0x01020304UL), ulong_2; unsigned long ulong_1(0x01020304UL), ulong_2;
ss <= ulong_1; ss.clear();
ss >= ulong_2; ss << bin(ulong_1);
BOOST_VERIFY( ulong_1 == ulong_2 ); ss >> bin(ulong_2);
BOOST_TEST( ulong_1 == ulong_2 );
long long long_long_1(0x0102030405060708LL), long_long_2; long long long_long_1(0x0102030405060708LL), long_long_2;
ss <= long_long_1; ss.clear();
ss >= long_long_2; ss << bin(long_long_1);
BOOST_VERIFY( long_long_1 == long_long_2 ); ss >> bin(long_long_2);
BOOST_TEST( long_long_1 == long_long_2 );
unsigned long long ulong_long_1(0x0102030405060708ULL), ulong_long_2; unsigned long long ulong_long_1(0x0102030405060708ULL), ulong_long_2;
ss <= ulong_long_1; ss.clear();
ss >= ulong_long_2; ss << bin(ulong_long_1);
BOOST_VERIFY( ulong_long_1 == ulong_long_2 ); ss >> bin(ulong_long_2);
BOOST_TEST( ulong_long_1 == ulong_long_2 );
float float_1(1.2F), float_2; float float_1(1.2F), float_2;
ss <= float_1; ss.clear();
ss >= float_2; ss << bin(float_1);
BOOST_VERIFY( float_1 == float_2 ); ss >> bin(float_2);
BOOST_TEST( float_1 == float_2 );
double double_1(1.2), double_2; double double_1(1.2), double_2;
ss <= double_1; ss.clear();
ss >= double_2; ss << bin(double_1);
BOOST_VERIFY( double_1 == double_2 ); ss >> bin(double_2);
BOOST_TEST( double_1 == double_2 );
long double long_double_1(1.2), long_double_2; long double long_double_1(1.2), long_double_2;
ss <= long_double_1; ss.clear();
ss >= long_double_2; ss << bin(long_double_1);
BOOST_VERIFY( long_double_1 == long_double_2 ); ss >> bin(long_double_2);
BOOST_TEST( long_double_1 == long_double_2 );
char char_1(0x01), char_2; char char_1(0x01), char_2;
ss <= char_1; ss.clear();
ss >= char_2; ss << bin(char_1);
BOOST_VERIFY( char_1 == char_2 ); ss >> bin(char_2);
BOOST_TEST( char_1 == char_2 );
signed char schar_1(0x01), schar_2; signed char schar_1(0x01), schar_2;
ss <= schar_1; ss.clear();
ss >= schar_2; ss << bin(schar_1);
BOOST_VERIFY( schar_1 == schar_2 ); ss >> bin(schar_2);
BOOST_TEST( schar_1 == schar_2 );
unsigned char uchar_1(0x01), uchar_2; unsigned char uchar_1(0x01), uchar_2;
ss <= uchar_1; ss.clear();
ss >= uchar_2; ss << bin(uchar_1);
BOOST_VERIFY( uchar_1 == uchar_2 ); ss >> bin(uchar_2);
BOOST_TEST( uchar_1 == uchar_2 );
wchar_t wchar_t_1(L'1'), wchar_t_2; wchar_t wchar_t_1(L'1'), wchar_t_2;
ss <= wchar_t_1; ss.clear();
ss >= wchar_t_2; ss << bin(wchar_t_1);
BOOST_VERIFY( wchar_t_1 == wchar_t_2 ); ss >> bin(wchar_t_2);
BOOST_TEST( wchar_t_1 == wchar_t_2 );
string string_1("foobar"), string_2; return ::boost::report_errors();
ss <= string_1.c_str();
ss >= string_2;
BOOST_VERIFY( string_1 == string_2 );
ss <= string_1;
ss >= string_2;
BOOST_VERIFY( string_1 == string_2 );
cout << errors << " error(s) detected\n";
return errors;
} }