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33 Commits

Author SHA1 Message Date
nobody
4d452a1170 This commit was manufactured by cvs2svn to create tag
'Version_1_25_0'.

[SVN r11317]
2001-10-01 16:59:12 +00:00
Beman Dawes
117720a8bc 1.25.0 Final runup
[SVN r11315]
2001-10-01 15:54:23 +00:00
Beman Dawes
a6f6c3613a Change comments to make it clear why forward declaration header is required.
[SVN r11314]
2001-10-01 14:15:44 +00:00
Darin Adler
7914f5b931 Fixed unused variables that show up as warnings when doing regression
tests.


[SVN r11241]
2001-09-24 23:21:16 +00:00
John Maddock
a1add0a6f6 Intel C++ fixes: Added class copy constructor.
[SVN r11200]
2001-09-22 11:52:56 +00:00
Beman Dawes
c032b337c4 Fix broken links and other HTML changes related to new config system
[SVN r11142]
2001-09-18 21:24:51 +00:00
Jens Maurer
ec363261ae remove "explicit" on two- and three-argument constructors to avoid
error on HP aCC


[SVN r11097]
2001-09-11 18:42:25 +00:00
Beman Dawes
97cde2183d Initial base_from_member commit
[SVN r11086]
2001-09-10 14:04:28 +00:00
Dave Abrahams
7f43c682db Fixed the pair_generator documentation. Order of parameters was wrong; reordered
the table to match the corrected order.


[SVN r11035]
2001-09-05 16:29:29 +00:00
Jeremy Siek
0c9eee3c6b changed note about the move to the tuples library
[SVN r10972]
2001-08-30 19:45:19 +00:00
John Maddock
3b1afa3ba6 changed "empty-member" to "empty base-class"
[SVN r10966]
2001-08-30 10:58:19 +00:00
Jeremy Siek
93e6a75125 changed #include for tie() to tuple.hpp
[SVN r10951]
2001-08-28 19:09:33 +00:00
Jeremy Siek
52f8a7c0ca changed #include for tie()
[SVN r10950]
2001-08-28 19:07:51 +00:00
Jeremy Siek
55bfeb646f removed tie() and class tied
[SVN r10938]
2001-08-26 19:55:49 +00:00
Jeremy Siek
75c9dd3be1 added not about constness of operator* and operator[]
[SVN r10931]
2001-08-24 15:28:20 +00:00
Dave Abrahams
6392e2788f Removed incorrect statics, added const
[SVN r10930]
2001-08-24 12:09:34 +00:00
Peter Dimov
6a97f3f9ba Tabs converted to spaces.
[SVN r10916]
2001-08-23 19:05:21 +00:00
Peter Dimov
6e5f52e279 initial commit
[SVN r10914]
2001-08-23 18:42:16 +00:00
Darin Adler
7f92bed902 Fix some broken links. Fix order of constructor initializers.
[SVN r10913]
2001-08-23 17:42:07 +00:00
Beman Dawes
d68a11cc42 Misc; mostly fix links to hard disk locations
[SVN r10902]
2001-08-20 13:04:43 +00:00
Beman Dawes
328a81e194 Fix broken hyperlink
[SVN r10896]
2001-08-19 15:08:33 +00:00
Beman Dawes
31d0908b74 Add workaround for BOOST_NO_STDC_NAMESPACE
[SVN r10681]
2001-07-20 21:29:36 +00:00
Dave Abrahams
32c77599f4 Fixes for ICL
[SVN r10613]
2001-07-14 12:51:59 +00:00
Beman Dawes
812ebf3562 Back out commit made in error
[SVN r10596]
2001-07-12 16:15:30 +00:00
Beman Dawes
37f476013d Change absolute URL's to relative
[SVN r10594]
2001-07-12 15:31:15 +00:00
Dave Abrahams
9f3104166f output_iterator_helper changes: removed default template parameters, added
support for self-proxying, additional documentation and tests (Aleksey Gurtovoy)


[SVN r10576]
2001-07-09 23:51:49 +00:00
Dave Abrahams
64cc0daf34 Integrate Aleksey's changes
[SVN r10575]
2001-07-09 23:50:55 +00:00
Beman Dawes
d5d64df124 Fix broken link
[SVN r10553]
2001-07-06 19:19:45 +00:00
Beman Dawes
0edcfcd5c1 Tuples library causes tie to be deprecated
[SVN r10552]
2001-07-06 19:16:39 +00:00
John Maddock
50ba2d419a Tweeked gcc workaround (gcc 3 still has same problem as gcc 2.9x), added tentative Metrowerks and Intel compiler workarounds.
[SVN r10422]
2001-06-25 11:31:14 +00:00
John Maddock
ff3a77ca5a Fixed problem with VC6 compilers - probably a temporary fix.
[SVN r10361]
2001-06-20 11:43:57 +00:00
Jens Maurer
4eaed6c23d remove superfluous, illegal "typename" (twice)
[SVN r10314]
2001-06-12 18:50:37 +00:00
Jeremy Siek
4d0dd46471 meant to add as a branch
[SVN r10280]
2001-06-06 19:16:34 +00:00
30 changed files with 1320 additions and 1114 deletions

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@@ -85,7 +85,7 @@ Once that is done we can drop Multi-Pass Input Iterator.
<TABLE>
<TR valign=top>
<TD nowrap>Copyright &copy 2000</TD><TD>
<A HREF=http://www.boost.org/people/jeremy_siek.htm>Jeremy Siek</A>, Univ.of Notre Dame (<A HREF="mailto:jsiek@lsc.nd.edu">jsiek@lsc.nd.edu</A>)
<a HREF="../../people/jeremy_siek.htm">Jeremy Siek</a>, Univ.of Notre Dame (<A HREF="mailto:jsiek@lsc.nd.edu">jsiek@lsc.nd.edu</A>)
</TD></TR></TABLE>
</BODY>

341
base_from_member.html Normal file
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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2//EN">
<html>
<head>
<title>Boost: Base-from-Member Idiom Documentation</title>
</head>
<body bgcolor="white" link="blue" text="black" vlink="purple" alink="red">
<h1><img src="../../c++boost.gif" alt="C++ Boost" align="middle"
width="277" height="86">Base-from-Member Idiom</h1>
<p>The class template <code>boost::base_from_member</code> provides
a workaround for a class that needs to initialize a base class with a
member. The class template is in <cite><a
href="../../boost/utility/base_from_member.hpp">boost/utility/base_from_member.hpp</a></cite>
which is included in <i><a href="../../boost/utility.hpp">boost/utility.hpp</a></i>.
The class template is forward declared in <i><a href="../../boost/utility_fwd.hpp">boost/utility_fwd.hpp</a></i>.</p>
<p>There is test/example code in <cite><a
href="base_from_member_test.cpp">base_from_member_test.cpp</a></cite>.</p>
<h2><a name="contents">Contents</a></h2>
<ul>
<li><a href="#contents">Contents</a></li>
<li><a href="#rationale">Rationale</a></li>
<li><a href="#synopsis">Synopsis</a></li>
<li><a href="#usage">Usage</a></li>
<li><a href="#example">Example</a></li>
<li><a href="#credits">Credits</a>
<ul>
<li><a href="#contributors">Contributors</a></li>
</ul></li>
</ul>
<h2><a name="rationale">Rationale</a></h2>
<p>When developing a class, sometimes a base class needs to be
initialized with a member of the current class. As a na&iuml;ve
example:</p>
<blockquote><pre>
#include &lt;streambuf&gt; <i>// for std::streambuf</i>
#include &lt;ostream&gt; <i>// for std::ostream</i>
class fdoutbuf
: public std::streambuf
{
public:
explicit fdoutbuf( int fd );
//...
};
class fdostream
: public std::ostream
{
protected:
fdoutbuf buf;
public:
explicit fdostream( int fd )
: buf( fd ), std::ostream( &amp;buf )
{}
//...
};
</pre></blockquote>
<p>This is undefined because C++'s initialization order mandates that
the base class is initialized before the member it uses. Ron Klatchko
developed a way around this by using the initialization order in his
favor. Base classes are intialized in order of declaration, so moving
the desired member to another base class, that is initialized before the
desired base class, can ensure proper initialization.</p>
<p>A custom base class can be made for this idiom:</p>
<blockquote><pre>
#include &lt;streambuf&gt; <i>// for std::streambuf</i>
#include &lt;ostream&gt; <i>// for std::ostream</i>
class fdoutbuf
: public std::streambuf
{
public:
explicit fdoutbuf( int fd );
//...
};
struct fdostream_pbase
{
fdoutbuf sbuffer;
explicit fdostream_pbase( int fd )
: sbuffer( fd )
{}
};
class fdostream
: private fdostream_pbase
, public std::ostream
{
typedef fdostream_pbase pbase_type;
typedef std::ostream base_type;
public:
explicit fdostream( int fd )
: pbase_type( fd ), base_type( &amp;sbuffer )
{}
//...
};
</pre></blockquote>
<p>Other projects can use similar custom base classes. The technique is basic enough to make a template, with a sample template class in this library. The main template parameter is the type of the enclosed member. The template class has several (explicit) constructor member templates, which implicitly type the constructor arguments and pass them to the member. The template class uses implicit copy construction and assignment, cancelling them if the enclosed member is non-copyable.</p>
<p>Manually coding a base class may be better if the construction
and/or copying needs are too complex for the supplied template class,
or if the compiler is not advanced enough to use it.</p>
<p>Since base classes are unnamed, a class cannot have multiple (direct)
base classes of the same type. The supplied template class has an
extra template parameter, an integer, that exists solely to provide type
differentiation. This parameter has a default value so a single use of a
particular member type does not need to concern itself with the integer.</p>
<h2><a name="synopsis">Synopsis</a></h2>
<blockquote><pre>
template &lt; typename MemberType, int UniqueID = 0 &gt;
class boost::base_from_member
{
protected:
MemberType member;
explicit base_from_member();
template&lt; typename T1 &gt;
explicit base_from_member( T1 x1 );
//...
template&lt; typename T1, typename T2, typename T3 &gt;
explicit base_from_member( T1 x1, T2 x2, T3 x3 );
};
</pre></blockquote>
<p>The class template has a first template parameter
<var>MemberType</var> representing the type of the based-member.
It has a last template parameter <var>UniqueID</var>, that is an
<code>int</code>, to differentiate between multiple base classes that use
the same based-member type. The last template parameter has a default
value of zero if it is omitted. The class template has a protected
data member called <var>member</var> that the derived class can use
for later base classes (or itself).</p>
<p>There is a default constructor and several constructor member
templates. These constructor templates can take as many arguments
(currently up to three) as possible and pass them to a constructor of
the data member. Since C++ does not allow any way to explicitly state
the template parameters of a templated constructor, make sure that
the arguments are already close as possible to the actual type used in
the data member's desired constructor.</p>
<h2><a name="usage">Usage</a></h2>
<p>With the starting example, the <code>fdoutbuf</code> sub-object needs
to be encapsulated in a base class that is inheirited before
<code>std::ostream</code>.</p>
<blockquote><pre>
#include &lt;boost/utility/base_from_member.hpp&gt;
#include &lt;streambuf&gt; <i>// for std::streambuf</i>
#include &lt;ostream&gt; <i>// for std::ostream</i>
class fdoutbuf
: public std::streambuf
{
public:
explicit fdoutbuf( int fd );
//...
};
class fdostream
: private boost::base_from_member&lt;fdoutbuf&gt;
, public std::ostream
{
// Helper typedef's
typedef boost::base_from_member&lt;fdoutbuf&gt; pbase_type;
typedef std::ostream base_type;
public:
explicit fdostream( int fd )
: pbase_type( fd ), base_type( &amp;member )
{}
//...
};
</pre></blockquote>
<p>The base-from-member idiom is an implementation detail, so it
should not be visible to the clients (or any derived classes) of
<code>fdostream</code>. Due to the initialization order, the
<code>fdoutbuf</code> sub-object will get initialized before the
<code>std::ostream</code> sub-object does, making the former
sub-object safe to use in the latter sub-object's construction. Since the
<code>fdoutbuf</code> sub-object of the final type is the only sub-object
with the name &quot;member,&quot; that name can be used
unqualified within the final class.</p>
<h2><a name="example">Example</a></h2>
<p>The base-from-member class templates should commonly involve
only one base-from-member sub-object, usually for attaching a
stream-buffer to an I/O stream. The next example demonstrates how
to use multiple base-from-member sub-objects and the resulting
qualification issues.</p>
<blockquote><pre>
#include &lt;boost/utility/base_from_member.hpp&gt;
#include &lt;cstddef&gt; <i>// for NULL</i>
struct an_int
{
int y;
an_int( float yf );
};
class switcher
{
public:
switcher();
switcher( double, int * );
//...
};
class flow_regulator
{
public:
flow_regulator( switcher &amp;, switcher &amp; );
//...
};
template &lt; unsigned Size &gt;
class fan
{
public:
explicit fan( switcher );
//...
};
class system
: private boost::base_from_member&lt;an_int&gt;
, private boost::base_from_member&lt;switcher&gt;
, private boost::base_from_member&lt;switcher, 1&gt;
, private boost::base_from_member&lt;switcher, 2&gt;
, protected flow_regulator
, public fan&lt;6&gt;
{
// Helper typedef's
typedef boost::base_from_member&lt;an_int&gt; pbase0_type;
typedef boost::base_from_member&lt;switcher&gt; pbase1_type;
typedef boost::base_from_member&lt;switcher, 1&gt; pbase2_type;
typedef boost::base_from_member&lt;switcher, 2&gt; pbase3_type;
typedef flow_regulator base1_type;
typedef fan&lt;6&gt; base2_type;
public:
system( double x );
//...
};
system::system( double x )
: pbase0_type( 0.2 )
, pbase1_type()
, pbase2_type( -16, &amp;this-&gt;pbase0_type::member )
, pbase3_type( x, static_cast&lt;int *&gt;(NULL) )
, base1_type( pbase3_type::member, pbase1_type::member )
, base2_type( pbase2_type::member )
{
//...
}
</pre></blockquote>
<p>The final class has multiple sub-objects with the name
&quot;member,&quot; so any use of that name needs qualification by
a name of the appropriate base type. (Using <code>typedef</code>s
ease mentioning the base types.) However, the fix introduces a new
problem when a pointer is needed. Using the address operator with
a sub-object qualified with its class's name results in a pointer-to-member
(here, having a type of <code>an_int boost::base_from_member&lt;an_int,
0&gt; :: *</code>) instead of a pointer to the member (having a type of
<code>an_int *</code>). The new problem is fixed by qualifying the
sub-object with &quot;<code>this-&gt;</code>,&quot; and is needed just
for pointers, and not for references or values.</p>
<p>There are some argument conversions in the initialization. The
constructor argument for <code>pbase0_type</code> is converted from
<code>double</code> to <code>float</code>. The first constructor
argument for <code>pbase2_type</code> is converted from <code>int</code>
to <code>double</code>. The second constructor argument for
<code>pbase3_type</code> is a special case of necessary conversion; all
forms of the null-pointer literal in C++ also look like compile-time
integral expressions, so C++ always interprets such code as an integer
when it has overloads that can take either an integer or a pointer. The
last conversion is necessary for the compiler to call a constructor form
with the exact pointer type used in <code>switcher</code>'s constructor.</p>
<h2><a name="credits">Credits</a></h2>
<h3><a name="contributors">Contributors</a></h3>
<dl>
<dt><a href="../../people/ed_brey.htm">Ed Brey</a>
<dd>Suggested some interface changes.
<dt>Ron Klatchko (<a href="mailto:ron@crl.com">ron@crl.com</a>)
<dd>Invented the idiom of how to use a class member for initializing
a base class.
<dt><a href="../../people/dietmar_kuehl.htm">Dietmar Kuehl</a>
<dd>Popularized the base-from-member idiom in his
<a href="http://www.informatik.uni-konstanz.de/~kuehl/c++/iostream/">IOStream
example classes</a>.
<dt><a href="../../people/daryle_walker.html">Daryle Walker</a>
<dd>Started the library. Contributed the test file <cite><a
href="base_from_member_test.cpp">base_from_member_test.cpp</a></cite>.
</dl>
<hr>
<p>Revised: 22 August 2001</p>
<p>Copyright &copy; boost.org 2001. Permission to copy, use, modify,
sell and distribute this document is granted provided this copyright
notice appears in all copies. This document is provided &quot;as
is&quot; without express or implied warranty, and with no claim as to
its suitability for any purpose.</p>
</body>
</html>

597
base_from_member_test.cpp Normal file
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// Boost test program for base-from-member class templates -----------------//
// (C) Copyright Daryle Walker 2001. Permission to copy, use, modify, sell
// and distribute this software is granted provided this copyright
// notice appears in all copies. This software is provided "as is" without
// express or implied warranty, and with no claim as to its suitability for
// any purpose.
// See http://www.boost.org for most recent version including documentation.
// Revision History
// 29 Aug 2001 Initial Version (Daryle Walker)
#define BOOST_INCLUDE_MAIN
#include <boost/test/test_tools.hpp> // for BOOST_TEST, main
#include <boost/config.hpp> // for BOOST_NO_MEMBER_TEMPLATES
#include <boost/cstdlib.hpp> // for boost::exit_success
#include <boost/utility.hpp> // for boost::noncopyable
#include <boost/utility/base_from_member.hpp> // for boost::base_from_member
#include <functional> // for std::binary_function, std::less
#include <iostream> // for std::cout (std::ostream, std::endl indirectly)
#include <set> // for std::set
#include <typeinfo> // for std::type_info
#include <utility> // for std::pair, std::make_pair
#include <vector> // for std::vector
// Control if extra information is printed
#ifndef CONTROL_EXTRA_PRINTING
#define CONTROL_EXTRA_PRINTING 1
#endif
// A (sub)object can be identified by its memory location and its type.
// Both are needed since an object can start at the same place as its
// first base class subobject and/or contained subobject.
typedef std::pair< void *, std::type_info const * > object_id;
// Object IDs need to be printed
std::ostream & operator <<( std::ostream &os, object_id const &oi );
// A way to generate an object ID
template < typename T >
object_id identify( T &obj );
// A custom comparison type is needed
struct object_id_compare
: std::binary_function<object_id, object_id, bool>
{
bool operator ()( object_id const &a, object_id const &b ) const;
}; // object_id_compare
// A singleton of this type coordinates the acknowledgements
// of objects being created and used.
class object_registrar
: boost::noncopyable
{
public:
#ifndef BOOST_NO_MEMBER_TEMPLATES
template < typename T >
void register_object( T &obj )
{ this->register_object_imp( identify(obj) ); }
template < typename T, typename U >
void register_use( T &owner, U &owned )
{ this->register_use_imp( identify(owner), identify(owned) ); }
template < typename T, typename U >
void unregister_use( T &owner, U &owned )
{ this->unregister_use_imp( identify(owner), identify(owned) ); }
template < typename T >
void unregister_object( T &obj )
{ this->unregister_object_imp( identify(obj) ); }
#endif
void register_object_imp( object_id obj );
void register_use_imp( object_id owner, object_id owned );
void unregister_use_imp( object_id owner, object_id owned );
void unregister_object_imp( object_id obj );
typedef std::set<object_id, object_id_compare> set_type;
typedef std::vector<object_id> error_record_type;
typedef std::vector< std::pair<object_id, object_id> > error_pair_type;
set_type db_;
error_pair_type defrauders_in_, defrauders_out_;
error_record_type overeager_, overkilled_;
}; // object_registrar
// A sample type to be used by containing types
class base_or_member
{
public:
explicit base_or_member( int x = 1, double y = -0.25 );
~base_or_member();
}; // base_or_member
// A sample type that uses base_or_member, used
// as a base for the main demonstration classes
class base_class
{
public:
explicit base_class( base_or_member &x, base_or_member *y = 0,
base_or_member *z = 0 );
~base_class();
private:
base_or_member *x_, *y_, *z_;
}; // base_class
// This bad class demonstrates the direct method of a base class needing
// to be initialized by a member. This is improper since the member
// isn't initialized until after the base class.
class bad_class
: public base_class
{
public:
bad_class();
~bad_class();
private:
base_or_member x_;
}; // bad_class
// The first good class demonstrates the correct way to initialize a
// base class with a member. The member is changed to another base
// class, one that is initialized before the base that needs it.
class good_class_1
: private boost::base_from_member<base_or_member>
, public base_class
{
typedef boost::base_from_member<base_or_member> pbase_type;
typedef base_class base_type;
public:
good_class_1();
~good_class_1();
}; // good_class_1
// The second good class also demonstrates the correct way to initialize
// base classes with other subobjects. This class uses the other helpers
// in the library, and shows the technique of using two base subobjects
// of the "same" type.
class good_class_2
: private boost::base_from_member<base_or_member, 0>
, private boost::base_from_member<base_or_member, 1>
, private boost::base_from_member<base_or_member, 2>
, public base_class
{
typedef boost::base_from_member<base_or_member, 0> pbase_type0;
typedef boost::base_from_member<base_or_member, 1> pbase_type1;
typedef boost::base_from_member<base_or_member, 2> pbase_type2;
typedef base_class base_type;
public:
good_class_2();
~good_class_2();
}; // good_class_2
// Declare/define the single object registrar
object_registrar obj_reg;
// Main functionality
int
test_main( int , char * [] )
{
BOOST_TEST( obj_reg.db_.empty() );
BOOST_TEST( obj_reg.defrauders_in_.empty() );
BOOST_TEST( obj_reg.defrauders_out_.empty() );
BOOST_TEST( obj_reg.overeager_.empty() );
BOOST_TEST( obj_reg.overkilled_.empty() );
// Make a separate block to examine pre- and post-effects
{
using std::cout;
using std::endl;
bad_class bc;
BOOST_TEST( obj_reg.db_.size() == 3 );
BOOST_TEST( obj_reg.defrauders_in_.size() == 1 );
good_class_1 gc1;
BOOST_TEST( obj_reg.db_.size() == 6 );
BOOST_TEST( obj_reg.defrauders_in_.size() == 1 );
good_class_2 gc2;
BOOST_TEST( obj_reg.db_.size() == 11 );
BOOST_TEST( obj_reg.defrauders_in_.size() == 1 );
BOOST_TEST( obj_reg.defrauders_out_.empty() );
BOOST_TEST( obj_reg.overeager_.empty() );
BOOST_TEST( obj_reg.overkilled_.empty() );
// Getting the addresses of the objects ensure
// that they're used, and not optimized away.
cout << "Object 'bc' is at " << &bc << '.' << endl;
cout << "Object 'gc1' is at " << &gc1 << '.' << endl;
cout << "Object 'gc2' is at " << &gc2 << '.' << endl;
}
BOOST_TEST( obj_reg.db_.empty() );
BOOST_TEST( obj_reg.defrauders_in_.size() == 1 );
BOOST_TEST( obj_reg.defrauders_out_.size() == 1 );
BOOST_TEST( obj_reg.overeager_.empty() );
BOOST_TEST( obj_reg.overkilled_.empty() );
return boost::exit_success;
}
// Print an object's ID
std::ostream &
operator <<
(
std::ostream & os,
object_id const & oi
)
{
// I had an std::ostringstream to help, but I did not need it since
// the program never screws around with formatting. Worse, using
// std::ostringstream is an issue with some compilers.
return os << '[' << ( oi.second ? oi.second->name() : "NOTHING" )
<< " at " << oi.first << ']';
}
// Get an object ID given an object
template < typename T >
inline
object_id
identify
(
T & obj
)
{
return std::make_pair( static_cast<void *>(&obj), &(typeid( obj )) );
}
// Compare two object IDs
bool
object_id_compare::operator ()
(
object_id const & a,
object_id const & b
) const
{
std::less<void *> vp_cmp;
if ( vp_cmp(a.first, b.first) )
{
return true;
}
else if ( vp_cmp(b.first, a.first) )
{
return false;
}
else
{
// object pointers are equal, compare the types
if ( a.second == b.second )
{
return false;
}
else if ( !a.second )
{
return true; // NULL preceeds anything else
}
else if ( !b.second )
{
return false; // NULL preceeds anything else
}
else
{
return a.second->before( *b.second );
}
}
}
// Let an object register its existence
void
object_registrar::register_object_imp
(
object_id obj
)
{
if ( db_.count(obj) <= 0 )
{
db_.insert( obj );
#if CONTROL_EXTRA_PRINTING
std::cout << "Registered " << obj << '.' << std::endl;
#endif
}
else
{
overeager_.push_back( obj );
#if CONTROL_EXTRA_PRINTING
std::cout << "Attempted to register a non-existant " << obj
<< '.' << std::endl;
#endif
}
}
// Let an object register its use of another object
void
object_registrar::register_use_imp
(
object_id owner,
object_id owned
)
{
if ( db_.count(owned) > 0 )
{
// We don't care to record usage registrations
}
else
{
defrauders_in_.push_back( std::make_pair(owner, owned) );
#if CONTROL_EXTRA_PRINTING
std::cout << "Attempted to own a non-existant " << owned
<< " by " << owner << '.' << std::endl;
#endif
}
}
// Let an object un-register its use of another object
void
object_registrar::unregister_use_imp
(
object_id owner,
object_id owned
)
{
if ( db_.count(owned) > 0 )
{
// We don't care to record usage un-registrations
}
else
{
defrauders_out_.push_back( std::make_pair(owner, owned) );
#if CONTROL_EXTRA_PRINTING
std::cout << "Attempted to disown a non-existant " << owned
<< " by " << owner << '.' << std::endl;
#endif
}
}
// Let an object un-register its existence
void
object_registrar::unregister_object_imp
(
object_id obj
)
{
set_type::iterator const i = db_.find( obj );
if ( i != db_.end() )
{
db_.erase( i );
#if CONTROL_EXTRA_PRINTING
std::cout << "Unregistered " << obj << '.' << std::endl;
#endif
}
else
{
overkilled_.push_back( obj );
#if CONTROL_EXTRA_PRINTING
std::cout << "Attempted to unregister a non-existant " << obj
<< '.' << std::endl;
#endif
}
}
// Macros to abstract the registration of objects
#ifndef BOOST_NO_MEMBER_TEMPLATES
#define PRIVATE_REGISTER_BIRTH(o) obj_reg.register_object( (o) )
#define PRIVATE_REGISTER_DEATH(o) obj_reg.unregister_object( (o) )
#define PRIVATE_REGISTER_USE(o, w) obj_reg.register_use( (o), (w) )
#define PRIVATE_UNREGISTER_USE(o, w) obj_reg.unregister_use( (o), (w) )
#else
#define PRIVATE_REGISTER_BIRTH(o) obj_reg.register_object_imp( \
identify((o)) )
#define PRIVATE_REGISTER_DEATH(o) obj_reg.unregister_object_imp( \
identify((o)) )
#define PRIVATE_REGISTER_USE(o, w) obj_reg.register_use_imp( identify((o)), \
identify((w)) )
#define PRIVATE_UNREGISTER_USE(o, w) obj_reg.unregister_use_imp( \
identify((o)), identify((w)) )
#endif
// Create a base_or_member, with arguments to simulate member initializations
base_or_member::base_or_member
(
int x, // = 1
double y // = -0.25
)
{
PRIVATE_REGISTER_BIRTH( *this );
#if CONTROL_EXTRA_PRINTING
std::cout << "\tMy x-factor is " << x << " and my y-factor is " << y
<< '.' << std::endl;
#endif
}
// Destroy a base_or_member
inline
base_or_member::~base_or_member
(
)
{
PRIVATE_REGISTER_DEATH( *this );
}
// Create a base_class, registering any objects used
base_class::base_class
(
base_or_member & x,
base_or_member * y, // = 0
base_or_member * z // = 0
)
: x_( &x ), y_( y ), z_( z )
{
PRIVATE_REGISTER_BIRTH( *this );
#if CONTROL_EXTRA_PRINTING
std::cout << "\tMy x-factor is " << x_;
#endif
PRIVATE_REGISTER_USE( *this, *x_ );
if ( y_ )
{
#if CONTROL_EXTRA_PRINTING
std::cout << ", my y-factor is " << y_;
#endif
PRIVATE_REGISTER_USE( *this, *y_ );
}
if ( z_ )
{
#if CONTROL_EXTRA_PRINTING
std::cout << ", my z-factor is " << z_;
#endif
PRIVATE_REGISTER_USE( *this, *z_ );
}
#if CONTROL_EXTRA_PRINTING
std::cout << '.' << std::endl;
#endif
}
// Destroy a base_class, unregistering the objects it uses
base_class::~base_class
(
)
{
PRIVATE_REGISTER_DEATH( *this );
#if CONTROL_EXTRA_PRINTING
std::cout << "\tMy x-factor was " << x_;
#endif
PRIVATE_UNREGISTER_USE( *this, *x_ );
if ( y_ )
{
#if CONTROL_EXTRA_PRINTING
std::cout << ", my y-factor was " << y_;
#endif
PRIVATE_UNREGISTER_USE( *this, *y_ );
}
if ( z_ )
{
#if CONTROL_EXTRA_PRINTING
std::cout << ", my z-factor was " << z_;
#endif
PRIVATE_UNREGISTER_USE( *this, *z_ );
}
#if CONTROL_EXTRA_PRINTING
std::cout << '.' << std::endl;
#endif
}
// Create a bad_class, noting the improper construction order
bad_class::bad_class
(
)
: x_( -7, 16.75 ), base_class( x_ ) // this order doesn't matter
{
PRIVATE_REGISTER_BIRTH( *this );
#if CONTROL_EXTRA_PRINTING
std::cout << "\tMy factor is at " << &x_
<< " and my base is at " << static_cast<base_class *>(this) << '.'
<< std::endl;
#endif
}
// Destroy a bad_class, noting the improper destruction order
bad_class::~bad_class
(
)
{
PRIVATE_REGISTER_DEATH( *this );
#if CONTROL_EXTRA_PRINTING
std::cout << "\tMy factor was at " << &x_
<< " and my base was at " << static_cast<base_class *>(this)
<< '.' << std::endl;
#endif
}
// Create a good_class_1, noting the proper construction order
good_class_1::good_class_1
(
)
: pbase_type( 8 ), base_type( member )
{
PRIVATE_REGISTER_BIRTH( *this );
#if CONTROL_EXTRA_PRINTING
std::cout << "\tMy factor is at " << &member
<< " and my base is at " << static_cast<base_class *>(this) << '.'
<< std::endl;
#endif
}
// Destroy a good_class_1, noting the proper destruction order
good_class_1::~good_class_1
(
)
{
PRIVATE_REGISTER_DEATH( *this );
#if CONTROL_EXTRA_PRINTING
std::cout << "\tMy factor was at " << &member
<< " and my base was at " << static_cast<base_class *>(this)
<< '.' << std::endl;
#endif
}
// Create a good_class_2, noting the proper construction order
good_class_2::good_class_2
(
)
: pbase_type0(), pbase_type1(-16, 0.125), pbase_type2(2, -3)
, base_type( pbase_type1::member, &this->pbase_type0::member,
&this->pbase_type2::member )
{
PRIVATE_REGISTER_BIRTH( *this );
#if CONTROL_EXTRA_PRINTING
std::cout << "\tMy factors are at " << &this->pbase_type0::member
<< ", " << &this->pbase_type1::member << ", "
<< &this->pbase_type2::member << ", and my base is at "
<< static_cast<base_class *>(this) << '.' << std::endl;
#endif
}
// Destroy a good_class_2, noting the proper destruction order
good_class_2::~good_class_2
(
)
{
PRIVATE_REGISTER_DEATH( *this );
#if CONTROL_EXTRA_PRINTING
std::cout << "\tMy factors were at " << &this->pbase_type0::member
<< ", " << &this->pbase_type1::member << ", "
<< &this->pbase_type2::member << ", and my base was at "
<< static_cast<base_class *>(this) << '.' << std::endl;
#endif
}

View File

@@ -17,6 +17,10 @@
#include <boost/call_traits.hpp>
#include <boost/type_traits/type_traits_test.hpp>
// a way prevent warnings for unused variables
template<class T> inline void unused_variable(const T&) {}
//
// struct contained models a type that contains a type (for example std::pair)
// arrays are contained by value, and have to be treated as a special case:
@@ -44,7 +48,7 @@ struct contained
reference get() { return v_; }
const_reference const_get()const { return v_; }
// pass value:
void call(param_type p){}
void call(param_type){}
};
@@ -69,7 +73,7 @@ struct contained<T[N]>
// return by_ref:
reference get() { return v_; }
const_reference const_get()const { return v_; }
void call(param_type p){}
void call(param_type){}
};
#endif
@@ -181,6 +185,12 @@ struct comparible_UDT
{
int i_;
comparible_UDT() : i_(2){}
comparible_UDT(const comparible_UDT& other) : i_(other.i_){}
comparible_UDT& operator=(const comparible_UDT& other)
{
i_ = other.i_;
return *this;
}
bool operator == (const comparible_UDT& v){ return v.i_ == i_; }
};
@@ -193,23 +203,23 @@ int main(int argc, char *argv[ ])
int i = 2;
c2(i);
int* pi = &i;
#if defined(BOOST_MSVC6_MEMBER_TEMPLATES) || !defined(BOOST_NO_MEMBER_TEMPLATES)
int a[2] = {1,2};
#if (defined(BOOST_MSVC6_MEMBER_TEMPLATES) || !defined(BOOST_NO_MEMBER_TEMPLATES)) && !defined(__ICL)
call_traits_checker<int*> c3;
c3(pi);
call_traits_checker<int&> c4;
c4(i);
call_traits_checker<const int&> c5;
c5(i);
#if !defined (BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION)
int a[2] = {1,2};
#if !defined (BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION) && !defined(__MWERKS__)
call_traits_checker<int[2]> c6;
c6(a);
#endif
#endif
check_wrap(wrap(2), 2);
const char ca[4] = "abc";
// compiler can't deduce this for some reason:
//const char ca[4] = "abc";
//check_wrap(wrap(ca), ca);
#ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
check_wrap(wrap(a), a);
@@ -238,7 +248,7 @@ int main(int argc, char *argv[ ])
type_test(int&, boost::call_traits<int&>::reference)
type_test(const int&, boost::call_traits<int&>::const_reference)
type_test(int&, boost::call_traits<int&>::param_type)
#if !(defined(__GNUC__) && (__GNUC__ < 3))
#if !(defined(__GNUC__) && (__GNUC__ < 4))
type_test(int&, boost::call_traits<cr_type>::value_type)
type_test(int&, boost::call_traits<cr_type>::reference)
type_test(const int&, boost::call_traits<cr_type>::const_reference)
@@ -312,6 +322,19 @@ void call_traits_test<T, isarray>::assert_construct(typename call_traits_test<T,
param_type p2(v);
param_type p3(r);
param_type p4(p);
unused_variable(v2);
unused_variable(v3);
unused_variable(v4);
unused_variable(r2);
unused_variable(r3);
unused_variable(cr2);
unused_variable(cr3);
unused_variable(cr4);
unused_variable(cr5);
unused_variable(p2);
unused_variable(p3);
unused_variable(p4);
}
#ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
template <typename T>
@@ -348,6 +371,17 @@ void call_traits_test<T, true>::assert_construct(typename boost::call_traits<T>:
param_type p2(v);
param_type p3(r);
param_type p4(p);
unused_variable(v2);
unused_variable(v3);
unused_variable(v4);
unused_variable(v5);
unused_variable(r2);
unused_variable(cr2);
unused_variable(cr3);
unused_variable(p2);
unused_variable(p3);
unused_variable(p4);
}
#endif //BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
//

View File

@@ -21,8 +21,8 @@ defined inside namespace boost.</p>
<p>The class compressed pair is very similar to std::pair, but if
either of the template arguments are empty classes, then the
&quot;empty member optimisation&quot; is applied to compress the
size of the pair.</p>
&quot;empty base-class optimisation&quot; is applied to compress
the size of the pair.</p>
<pre>template &lt;class T1, class T2&gt;
class compressed_pair

View File

@@ -199,7 +199,7 @@ struct compressed_pair_reference1_tester
};
template <class T1, class T2>
void compressed_pair_reference1_tester<T1, T2>::test(first_param_type p1, second_param_type p2, first_param_type p3, second_param_type p4)
void compressed_pair_reference1_tester<T1, T2>::test(first_param_type p1, second_param_type p2, first_param_type, second_param_type)
{
#ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
// first param construct:
@@ -225,7 +225,7 @@ struct compressed_pair_reference2_tester
};
template <class T1, class T2>
void compressed_pair_reference2_tester<T1, T2>::test(first_param_type p1, second_param_type p2, first_param_type p3, second_param_type p4)
void compressed_pair_reference2_tester<T1, T2>::test(first_param_type p1, second_param_type p2, first_param_type, second_param_type)
{
#ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
// second param construct:
@@ -252,7 +252,7 @@ struct compressed_pair_array1_tester
};
template <class T1, class T2>
void compressed_pair_array1_tester<T1, T2>::test(first_param_type p1, second_param_type p2, first_param_type p3, second_param_type p4)
void compressed_pair_array1_tester<T1, T2>::test(first_param_type p1, second_param_type p2, first_param_type, second_param_type)
{
// default construct:
boost::compressed_pair<T1,T2> cp1;
@@ -282,7 +282,7 @@ struct compressed_pair_array2_tester
};
template <class T1, class T2>
void compressed_pair_array2_tester<T1, T2>::test(first_param_type p1, second_param_type p2, first_param_type p3, second_param_type p4)
void compressed_pair_array2_tester<T1, T2>::test(first_param_type p1, second_param_type p2, first_param_type, second_param_type)
{
// default construct:
boost::compressed_pair<T1,T2> cp1;
@@ -312,7 +312,7 @@ struct compressed_pair_array_tester
};
template <class T1, class T2>
void compressed_pair_array_tester<T1, T2>::test(first_param_type p1, second_param_type p2, first_param_type p3, second_param_type p4)
void compressed_pair_array_tester<T1, T2>::test(first_param_type p1, second_param_type p2, first_param_type, second_param_type)
{
// default construct:
boost::compressed_pair<T1,T2> cp1;
@@ -329,7 +329,7 @@ void compressed_pair_array_tester<T1, T2>::test(first_param_type p1, second_para
BOOST_TEST(sizeof(T2) == sizeof(cp1.second()));
}
int test_main(int argc, char *argv[ ])
int test_main(int, char **)
{
// declare some variables to pass to the tester:
non_empty1 ne1(2);

View File

@@ -308,7 +308,7 @@ implementation, the <tt>difference_type</tt> for any variable-length signed
integer type <tt>T</tt> is <tt>T</tt> itself.
<hr>
<p>Revised <!--webbot bot="Timestamp" s-type="EDITED" s-format="%d %b %Y" startspan -->08 Mar 2001<!--webbot bot="Timestamp" endspan i-checksum="14892" --></p>
<p>Revised <!--webbot bot="Timestamp" s-type="EDITED" s-format="%d %b %Y" startspan -->19 Aug 2001<!--webbot bot="Timestamp" endspan i-checksum="14767" --></p>
<p><EFBFBD> Copyright Jeremy Siek 2000. Permission to copy, use,
modify, sell and distribute this document is granted provided this copyright
notice appears in all copies. This document is provided &quot;as is&quot;

View File

@@ -27,7 +27,7 @@
#include <climits>
#include <iterator>
#include <stdlib.h>
#include <boost/utility.hpp>
#include <boost/tuple/tuple.hpp>
#include <vector>
#include <list>
#include <cassert>

View File

@@ -9,6 +9,9 @@
// See http://www.boost.org for most recent version including documentation.
// Revision History
// 25 Jun 01 output_iterator_helper changes: removed default template
// parameters, added support for self-proxying, additional
// documentation and tests (Aleksey Gurtovoy)
// 29 May 01 Added operator classes for << and >>. Added input and output
// iterator helper classes. Added classes to connect equality and
// relational operators. Added classes for groups of related
@@ -702,15 +705,15 @@ struct input_iterator_helper
, boost::iterator<std::input_iterator_tag, V, D, P, R
> > > > {};
template <class T,
class V = void,
class D = void,
class P = void,
class R = void>
template<class Derived>
struct output_iterator_helper
: incrementable<T
, boost::iterator<std::output_iterator_tag, V, D, P, R
> > {};
: boost::incrementable<Derived
, boost::iterator<std::output_iterator_tag, void, void, void, void
> >
{
Derived& operator*() { return static_cast<Derived&>(*this); }
Derived& operator++() { return static_cast<Derived&>(*this); }
};
template <class T,
class V,

55
include/boost/ref.hpp Normal file
View File

@@ -0,0 +1,55 @@
#ifndef BOOST_REF_HPP_INCLUDED
#define BOOST_REF_HPP_INCLUDED
#if _MSC_VER >= 1020
#pragma once
#endif
//
// ref.hpp - ref/cref, useful helper functions
//
// Version 1.00.0003 (2001-08-22)
//
// Copyright (C) 1999, 2000 Jaakko J<>rvi (jaakko.jarvi@cs.utu.fi)
//
// Permission to copy, use, modify, sell and distribute this software
// is granted provided this copyright notice appears in all copies.
// This software is provided "as is" without express or implied
// warranty, and with no claim as to its suitability for any purpose.
//
// See http://www.boost.org/libs/bind/ref.html for documentation.
//
namespace boost
{
template<class T> class reference_wrapper
{
public:
explicit reference_wrapper(T & t): t_(t) {}
operator T & () const { return t_; }
T & get() const { return t_; }
private:
T & t_;
reference_wrapper & operator= (reference_wrapper const &);
};
template<class T> inline reference_wrapper<T> ref(T & t)
{
return reference_wrapper<T>(t);
}
template<class T> inline reference_wrapper<T const> cref(T const & t)
{
return reference_wrapper<T const>(t);
}
} // namespace boost
#endif // #ifndef BOOST_REF_HPP_INCLUDED

View File

@@ -10,23 +10,15 @@
// Classes appear in alphabetical order
// Revision History
// 21 May 01 checked_delete() and checked_array_delete() added (Beman Dawes,
// suggested by Dave Abrahams, generalizing idea from Vladimir Prus)
// 21 May 01 made next() and prior() inline (Beman Dawes)
// 26 Jan 00 protected noncopyable destructor added (Miki Jovanovic)
// 10 Dec 99 next() and prior() templates added (Dave Abrahams)
// 30 Aug 99 moved cast templates to cast.hpp (Beman Dawes)
// 3 Aug 99 cast templates added
// 20 Jul 99 name changed to utility.hpp
// 9 Jun 99 protected noncopyable default ctor
// 2 Jun 99 Initial Version. Class noncopyable only contents (Dave Abrahams)
#ifndef BOOST_UTILITY_HPP
#define BOOST_UTILITY_HPP
#include <boost/config.hpp> // broken compiler workarounds
#include <boost/static_assert.hpp>
#include <boost/config.hpp> // broken compiler workarounds
#include <boost/static_assert.hpp>
// certain headers are part of the <utility.hpp> interface
#include <boost/utility/base_from_member.hpp>
#include <cstddef> // for size_t
#include <utility> // for std::pair
@@ -87,31 +79,6 @@ namespace boost
const noncopyable& operator=( const noncopyable& );
}; // noncopyable
// class tied -------------------------------------------------------//
// A helper for conveniently assigning the two values from a pair
// into separate variables. The idea for this comes from Jaakko J<>rvi's
// Binder/Lambda Library.
// Constributed by Jeremy Siek
template <class A, class B>
class tied {
public:
inline tied(A& a, B& b) : _a(a), _b(b) { }
template <class U, class V>
inline tied& operator=(const std::pair<U,V>& p) {
_a = p.first;
_b = p.second;
return *this;
}
protected:
A& _a;
B& _b;
};
template <class A, class B>
inline tied<A,B> tie(A& a, B& b) { return tied<A,B>(a, b); }
} // namespace boost

View File

@@ -0,0 +1,59 @@
// boost utility/base_from_member.hpp header file --------------------------//
// (C) Copyright Daryle Walker 2001. Permission to copy, use, modify, sell
// and distribute this software is granted provided this copyright
// notice appears in all copies. This software is provided "as is" without
// express or implied warranty, and with no claim as to its suitability for
// any purpose.
// See http://www.boost.org for most recent version including documentation.
#ifndef BOOST_UTILITY_BASE_FROM_MEMBER_HPP
#define BOOST_UTILITY_BASE_FROM_MEMBER_HPP
#include <boost/utility_fwd.hpp> // required for parameter defaults
namespace boost
{
// Base-from-member class template -----------------------------------------//
// Helper to initialize a base object so a derived class can use this
// object in the initialization of another base class. Used by
// Dietmar Kuehl from ideas by Ron Klatcho to solve the problem of a
// base class needing to be initialized by a member.
// Contributed by Daryle Walker
template < typename MemberType, int UniqueID >
class base_from_member
{
protected:
MemberType member;
explicit base_from_member()
: member()
{}
template< typename T1 >
explicit base_from_member( T1 x1 )
: member( x1 )
{}
template< typename T1, typename T2 >
base_from_member( T1 x1, T2 x2 )
: member( x1, x2 )
{}
template< typename T1, typename T2, typename T3 >
base_from_member( T1 x1, T2 x2, T3 x3 )
: member( x1, x2, x3 )
{}
}; // boost::base_from_member
} // namespace boost
#endif // BOOST_UTILITY_BASE_FROM_MEMBER_HPP

View File

@@ -0,0 +1,38 @@
// Boost utility_fwd.hpp header file ---------------------------------------//
// (C) Copyright boost.org 2001. Permission to copy, use, modify, sell
// and distribute this software is granted provided this copyright
// notice appears in all copies. This software is provided "as is" without
// express or implied warranty, and with no claim as to its suitability for
// any purpose.
// See http://www.boost.org for most recent version including documentation.
#ifndef BOOST_UTILITY_FWD_HPP
#define BOOST_UTILITY_FWD_HPP
namespace boost
{
// From <boost/utility/base_from_member.hpp> -------------------------------//
template < typename MemberType, int UniqueID = 0 >
class base_from_member;
// From <boost/utility.hpp> ------------------------------------------------//
class noncopyable;
template < class A, class B >
class tied;
// Also has a few function templates
} // namespace boost
#endif // BOOST_UTILITY_FWD_HPP

View File

@@ -203,10 +203,10 @@ explicit indirect_iterator_generator::type(const BaseIterator&amp; it)
<blockquote>
<pre>
template &lt;class BaseIterator,
class Value, class Pointer, class Reference,
class ConstPointer, class ConstReference&gt;
class indirect_iterator_pair_generator
template &lt;class BaseIterator,
class Value, class Reference, class ConstReference,
class Category, class Pointer, class ConstPointer&gt;
struct indirect_iterator_pair_generator;
{
public:
typedef <tt><a href=
@@ -292,13 +292,6 @@ b,c,d,e,f,g,h,
in particular, the result type of its <tt>operator*()</tt>.<br>
<b>Default:</b> <tt>Value&amp;</tt>
<tr>
<td><tt>Pointer</tt>
<td>The <tt>pointer</tt> type of the resulting <tt>iterator</tt>, and
in particular, the result type of its <tt>operator-&gt;()</tt>.<br>
<b>Default:</b> <tt>Value*</tt>
<tr>
<td><tt>ConstReference</tt>
@@ -307,6 +300,19 @@ b,c,d,e,f,g,h,
<tt>operator*()</tt>.<br>
<b>Default:</b> <tt>const Value&amp;</tt>
<tr>
<td><tt>Category</tt>
<td>The <tt>iterator_category</tt> type for the resulting iterator.<br>
<b>Default:</b>
<tt>std::iterator_traits&lt;BaseIterator&gt;::iterator_category</tt>
<tr>
<td><tt>Pointer</tt>
<td>The <tt>pointer</tt> type of the resulting <tt>iterator</tt>, and
in particular, the result type of its <tt>operator-&gt;()</tt>.<br>
<b>Default:</b> <tt>Value*</tt>
<tr>
<td><tt>ConstPointer</tt>
@@ -314,11 +320,6 @@ b,c,d,e,f,g,h,
and in particular, the result type of its <tt>operator-&gt;()</tt>.<br>
<b>Default:</b> <tt>const Value*</tt>
<tr>
<td><tt>Category</tt>
<td>The <tt>iterator_category</tt> type for the resulting iterator.<br>
<b>Default:</b>
<tt>std::iterator_traits&lt;BaseIterator&gt;::iterator_category</tt>
</table>
<h3>Concept Model</h3>
@@ -422,7 +423,7 @@ a,b,c,d,e,f,g,
<hr>
<p>Revised
<!--webbot bot="Timestamp" s-type="EDITED" s-format="%d %b %Y" startspan -->08 Mar 2001<!--webbot bot="Timestamp" endspan i-checksum="14892" -->
<!--webbot bot="Timestamp" s-type="EDITED" s-format="%d %b %Y" startspan -->18 Sep 2001<!--webbot bot="Timestamp" endspan i-checksum="14941" -->
<p>&copy; Copyright Jeremy Siek and David Abrahams 2001. Permission to

View File

@@ -93,7 +93,7 @@
<a href="function_output_iterator.htm">Function Output Iterator Adaptor</a>
</ul>
<p><b><a href="http://www.boost.org/people/dave_abrahams.htm">Dave
<p><b><a href="../../people/dave_abrahams.htm">Dave
Abrahams</a></b> started the library, applying <a href=
"../../more/generic_programming.html#policy">policy class</a> technique and
handling const/non-const iterator interactions. He also contributed the
@@ -102,7 +102,7 @@
<tt><a href="counting_iterator.htm">counting_iterator_generator</a></tt> to
cover all incrementable types. He edited most of the documentation,
sometimes heavily.<br>
<b><a href="http://www.boost.org/people/jeremy_siek.htm">Jeremy
<b><a href="../../people/jeremy_siek.htm">Jeremy
Siek</a></b> contributed the <a href="transform_iterator.htm">transform
iterator</a> adaptor, the integer-only version of <tt><a href=
"counting_iterator.htm">counting_iterator_generator</a></tt>,
@@ -423,27 +423,27 @@ struct <a name="default_iterator_policies">default_iterator_policies</a>
{ return *x; }
template &lt;class BaseType&gt;
static void increment(BaseType&amp; x)
void increment(BaseType&amp; x)
{ ++x; }
template &lt;class BaseType1, class BaseType2&gt;
bool equal(BaseType1&amp; x, BaseType2&amp; y) const
bool equal(const BaseType1&amp; x, const BaseType2&amp; y) const
{ return x == y; }
template &lt;class BaseType&gt;
static void decrement(BaseType&amp; x)
void decrement(BaseType&amp; x)
{ --x; }
template &lt;class BaseType, class DifferenceType&gt;
static void advance(BaseType&amp; x, DifferenceType n)
void advance(BaseType&amp; x, DifferenceType n)
{ x += n; }
template &lt;class Difference, class BaseType1, class BaseType2&gt;
Difference distance(type&lt;Difference&gt;, BaseType1&amp; x, BaseType2&amp; y) const
Difference distance(type&lt;Difference&gt;, const BaseType1&amp; x, const BaseType2&amp; y) const
{ return y - x; }
template &lt;class BaseType1, class BaseType2&gt;
bool less(BaseType1&amp; x, BaseType2&amp; y) const
bool less(const BaseType1&amp; x, const BaseType2&amp; y) const
{ return x &lt; y; }
};
</pre>
@@ -611,10 +611,10 @@ int main(int, char*[])
{
int x[] = { 1, 2, 3, 4, 5, 6, 7, 8 };
const int N = sizeof(x)/sizeof(int);
std::cout &lt;&lt; "multiplying the array by 2:" &lt;&lt; std::endl;
std::cout &lt;&lt; &quot;multiplying the array by 2:&quot; &lt;&lt; std::endl;
std::copy(boost::make_transform_iterator(x, std::bind1st(std::multiplies&lt;int&gt;(), 2)),
boost::make_transform_iterator(x + N, std::bind1st(std::multiplies&lt;int&gt;(), 2)),
std::ostream_iterator&lt;int&gt;(std::cout, " "));
std::ostream_iterator&lt;int&gt;(std::cout, &quot; &quot;));
std::cout &lt;&lt; std::endl;
return 0;
}
@@ -767,10 +767,10 @@ struct iterator_adaptor
iterator_adaptor(
const iterator_adaptor&lt;B,Policies,V,R,P,Category,Distance&gt;&amp;);
reference operator*() const;
reference operator*() const; <a href="#6">[6]</a>
<i>operator_arrow_result_type</i> operator-&gt;() const; <a href=
"#3">[3]</a>
<i>value_type</i> operator[](difference_type n) const; <a href="#3">[4]</a>
<i>value_type</i> operator[](difference_type n) const; <a href="#3">[4]</a>, <a href="#6">[6]</a>
iterator_adaptor&amp; operator++();
iterator_adaptor&amp; operator++(int);
@@ -857,10 +857,38 @@ bool operator==(const iterator_adaptor&lt;B1,P,V1,R1,P1,C,D&gt;&amp;,
Forward Iterator</a>, so you will need to use a less restrictive
iterator category such as <tt>std::input_iterator_tag</tt>.
<p><a name="6">[6]</a>
There is a common misconception that an iterator should have two
versions of <tt>operator*</tt> and of <tt>operator[]</tt>, one
version that is a <tt>const</tt> member function and one version
that is non-<tt>const</tt>. Perhaps the source of this
misconception is that containers typically have const and
non-const versions of many of their member functions. Iterators,
however, are different. A particular iterator type can be either
<i>mutable</i> or <i>constant</i> (but not both). One can assign
to and change the object pointed to by a mutable iterator whereas a
constant iterator returns constant objects when dereferenced. Whether
the iterator object itself is <tt>const</tt> has nothing to do with
whether the iterator is mutable or constant. This is analogous to
the way built-in pointer types behave. For example, one can
modify objects pointed to by a <tt>const</tt> pointer
<pre>
int* const x = new int;
int i = 3;
*x = i;
</pre>
but one cannot modify objects pointed to by a pointer
to <tt>const</tt>
<pre>
int const* x = new int;
int i = 3;
*x = i;
</pre>
<hr>
<p>Revised
<!--webbot bot="Timestamp" s-type="EDITED" s-format="%d %b %Y" startspan -->19 Mar 2001<!--webbot bot="Timestamp" endspan i-checksum="14895" -->
<!--webbot bot="Timestamp" s-type="EDITED" s-format="%d %b %Y" startspan -->18 Sep 2001<!--webbot bot="Timestamp" endspan i-checksum="14941" -->
<p>&copy; Copyright Dave Abrahams and Jeremy Siek 2001. Permission to copy,
@@ -871,7 +899,7 @@ bool operator==(const iterator_adaptor&lt;B1,P,V1,R1,P1,C,D&gt;&amp;,
</body>
<!-- LocalWords: HTML html charset alt gif abrahams htm const
<!-- LocalWords: HTML html charset alt gif abrahams htm const iterator
incrementable david abrahams
-->
@@ -887,5 +915,7 @@ bool operator==(const iterator_adaptor&lt;B1,P,V1,R1,P1,C,D&gt;&amp;,
<!-- LocalWords: iostream hpp sizeof InputIterator constness ConstIterator
David Abrahams
-->
<!-- LocalWords: Iterators dereferenced
-->
</html>

View File

@@ -26,6 +26,10 @@
#include <string> // for std::string
#include <strstream> // for std::ostrstream
# ifdef BOOST_NO_STDC_NAMESPACE
namespace std { using ::strcmp; }
# endif
// Iterator test class
template <class T, class R, class P>
@@ -106,10 +110,10 @@ private:
// Class-static data definitions
typename test_opr_base::fruit_array_type
test_opr_base::fruit_array_type
test_opr_base::fruit = { "apple", "orange", "pear", "peach", "grape", "plum" };
typename test_opr_base::scratch_array_type
test_opr_base::scratch_array_type
test_opr_base::scratch = "";
template <typename T, typename R, typename P>

View File

@@ -7,6 +7,7 @@
// See http://www.boost.org for most recent version including documentation.
// Revision History
// 1 Apr 2001 Fixes for ICL; use BOOST_STATIC_CONSTANT
// 11 Feb 2001 Fixes for Borland (David Abrahams)
// 23 Jan 2001 Added test for wchar_t (David Abrahams)
// 23 Jan 2001 Now statically selecting a test for signed numbers to avoid
@@ -30,13 +31,6 @@
# include <limits>
#endif
// A macro for declaring class compile-time constants.
#ifndef BOOST_NO_INCLASS_MEMBER_INITIALIZATION
# define DECLARE_CLASS_CONST(type, init) static const type init
#else
# define DECLARE_CLASS_CONST(type, init) enum { init }
#endif
// =================================================================================
// template class complement_traits<Number> --
//
@@ -53,8 +47,8 @@ template <unsigned size> struct complement; // forward
template <class Number, unsigned size>
struct complement_traits_aux
{
DECLARE_CLASS_CONST(Number, max = complement<size>::template traits<Number>::max);
DECLARE_CLASS_CONST(Number, min = complement<size>::template traits<Number>::min);
BOOST_STATIC_CONSTANT(Number, max = complement<size>::template traits<Number>::max);
BOOST_STATIC_CONSTANT(Number, min = complement<size>::template traits<Number>::min);
};
template <unsigned size>
@@ -67,11 +61,11 @@ struct complement
// indirection through complement_traits_aux neccessary to keep MSVC happy
typedef complement_traits_aux<Number, size - 1> prev;
public:
DECLARE_CLASS_CONST(Number, max =
BOOST_STATIC_CONSTANT(Number, max =
Number(Number(prev::max) << CHAR_BIT)
+ Number(UCHAR_MAX));
DECLARE_CLASS_CONST(Number, min = Number(Number(prev::min) << CHAR_BIT));
BOOST_STATIC_CONSTANT(Number, min = Number(Number(prev::min) << CHAR_BIT));
};
};
@@ -85,8 +79,8 @@ template <> struct complement_base<false>
template <class Number>
struct values
{
DECLARE_CLASS_CONST(Number, min = 0);
DECLARE_CLASS_CONST(Number, max = UCHAR_MAX);
BOOST_STATIC_CONSTANT(Number, min = 0);
BOOST_STATIC_CONSTANT(Number, max = UCHAR_MAX);
};
};
@@ -95,8 +89,8 @@ template <> struct complement_base<true>
template <class Number>
struct values
{
DECLARE_CLASS_CONST(Number, min = SCHAR_MIN);
DECLARE_CLASS_CONST(Number, max = SCHAR_MAX);
BOOST_STATIC_CONSTANT(Number, min = SCHAR_MIN);
BOOST_STATIC_CONSTANT(Number, max = SCHAR_MAX);
};
};
@@ -107,10 +101,10 @@ struct complement<1>
template <class Number>
struct traits
{
DECLARE_CLASS_CONST(bool, is_signed = boost::detail::is_signed<Number>::value);
DECLARE_CLASS_CONST(Number, min =
BOOST_STATIC_CONSTANT(bool, is_signed = boost::detail::is_signed<Number>::value);
BOOST_STATIC_CONSTANT(Number, min =
complement_base<is_signed>::template values<Number>::min);
DECLARE_CLASS_CONST(Number, max =
BOOST_STATIC_CONSTANT(Number, max =
complement_base<is_signed>::template values<Number>::max);
};
};
@@ -121,8 +115,8 @@ struct complement<1>
template <class Number>
struct complement_traits
{
DECLARE_CLASS_CONST(Number, max = (complement_traits_aux<Number, sizeof(Number)>::max));
DECLARE_CLASS_CONST(Number, min = (complement_traits_aux<Number, sizeof(Number)>::min));
BOOST_STATIC_CONSTANT(Number, max = (complement_traits_aux<Number, sizeof(Number)>::max));
BOOST_STATIC_CONSTANT(Number, min = (complement_traits_aux<Number, sizeof(Number)>::min));
};
// =================================================================================
@@ -151,9 +145,9 @@ template <> struct stream_as<signed char> {
typedef unsigned char t1; typedef unsigned t2;
};
#if defined(BOOST_MSVC) // No intmax streaming built-in
#if defined(BOOST_MSVC_STD_ITERATOR) // No intmax streaming built-in
// On this platform, __int64 and __uint64 get streamed as strings
// With this library implementation, __int64 and __uint64 get streamed as strings
template <> struct stream_as<boost::uintmax_t> {
typedef std::string t1;
typedef std::string t2;
@@ -174,7 +168,7 @@ template <class T> struct promote
}
};
#if defined(BOOST_MSVC) // No intmax streaming built-in
#if defined(BOOST_MSVC_STD_ITERATOR) // No intmax streaming built-in
// On this platform, stream them as long/unsigned long if they fit.
// Otherwise, write a string.

View File

@@ -50,6 +50,7 @@ provided by the class.</p>
<ul>
<li><a href="#dereference">Dereference operators</a></li>
<li><a href="#iterator">Iterator Helpers</a></li>
<li><a href="#iterator_helpers_notes">Iterator Helper Notes</a></li>
<li><a href="#i_demo">Iterator Demonstration and Test
Program</a></li>
</ul></li>
@@ -821,7 +822,7 @@ from previous versions of the header, cannot be used for
<p>The <cite><a href="operators_test.cpp">operators_test.cpp</a></cite>
program demonstrates the use of the arithmetic operator templates, and
can also be used to verify correct operation. Check the <a
href="../compiler_status.htm">compiler status report</a> for the test results
href="../../status/compiler_status.html">compiler status report</a> for the test results
with selected platforms.</p>
<h2><a name="deref">Dereference</a> Operators and Iterator Helpers</h2>
@@ -889,7 +890,7 @@ href="#chaining">base class chaining</a>.</p>
<h3><a name="iterator">Iterator</a> Helpers</h3>
<p>There are three separate iterator helper classes, each for a
<p>There are five separate iterator helper classes, each for a
different category of iterator. Here is a summary of the core set of
operators that the custom iterator must define, and the extra operators
that are created by the helper classes. These classes cannot be used for <a
@@ -931,11 +932,13 @@ C++ standard (<code>iterator_category</code>, <code>value_type</code>,
</ul></td>
</tr>
<tr valign="baseline">
<td><code><a name="output_iterator_helper">output_iterator_helper&lt;T, V, D, P, R&gt;</a></code></td>
<td><code><a name="output_iterator_helper">output_iterator_helper&lt;T&gt;</a></code></td>
<td>Supports the operations and has the requirements of
<ul>
<li><code><a href="#incrementable">incrementable&lt;T&gt;</a></code></li>
</ul></td>
</ul>
See also [<a href="#1">1</a>], [<a href="#2">2</a>].
</td>
</tr>
<tr valign="baseline">
<td><code><a name="forward_iterator_helper">forward_iterator_helper&lt;T, V, D, P, R&gt;</a></code></td>
@@ -975,6 +978,53 @@ C++ standard (<code>iterator_category</code>, <code>value_type</code>,
</tr>
</table>
<h3><a name="iterator_helpers_notes">Iterator Helper Notes</a></h3>
<p><a name="1">[1]</a> Unlike other iterator helpers templates,
<code>output_iterator_helper</code> takes only one template parameter - the type of
its target class. Although to some it might seem like an unnecessary
restriction, the standard requires <code>difference_type</code> and
<code>value_type</code> of any output iterator to be
<code>void</code> (24.3.1 [lib.iterator.traits]), and
<code>output_iterator_helper</code> template respects this
requirement. Also, output iterators in the standard have void <tt>pointer</tt> and
<tt>reference</tt> types, so the <tt>output_iterator_helper</tt> does the
same.
<p><a name="2">[2]</a> As self-proxying is the easiest and most common way to
implement output iterators (see, for example, insert [24.4.2] and stream
iterators [24.5] in the standard library), <code>output_iterator_helper</code>
supports the idiom by defining <code>operator*</code>
and <code>operator++</code> member functions which just return a
non-const reference to the iterator itself. Support for
self-proxying allows us, in many cases, to reduce the task of writing an output
iterator to writing just two member functions - an appropriate
constructor and a copy-assignment operator. For example, here is a possible
implementation of <code><a href="function_output_iterator.htm">boost::function_output_iterator</a></code>
adaptor:</p>
<pre>
template&lt;class UnaryFunction&gt;
struct function_output_iterator
: boost::output_iterator_helper&lt; function_output_iterator&lt;UnaryFunction&gt; &gt;
{
explicit function_output_iterator(UnaryFunction const& f = UnaryFunction())
: func(f) {}
template&lt;typename T&gt;
function_output_iterator& operator=(T const& value)
{
this->func(value);
return *this;
}
private:
UnaryFunction func;
};
</pre>
<p>Note that support for self-proxying does not prevent you from using <code>output_iterator_helper</code> to ease any other, different kind of output iterator's implementation. If <code>output_iterator_helper</code>'s target type provides its own definition of <code>operator*</code> or/and <code>operator++</code>, then these operators will get used and the ones supplied by <code>output_iterator_helper</code> will never be instantiated.</p>
<h3><a name="i_demo">Iterator Demonstration</a> and Test Program</h3>
<p>The <cite><a href="iterators_test.cpp">iterators_test.cpp</a></cite>
@@ -1010,7 +1060,7 @@ public:
};</pre>
</blockquote>
<p>Check the <a href="../compiler_status.htm">compiler status report</a> for
<p>Check the <a href="../../status/compiler_status.html">compiler status report</a> for
the test results with selected platforms.</p>
<hr>
@@ -1092,7 +1142,7 @@ the library remain backward-compatible.</p>
<hr>
<p>Revised: 20 May 2001</p>
<p>Revised: 25 Jun 2001</p>
<p>Copyright &copy; David Abrahams and Beman Dawes 1999-2001.
Permission to copy, use, modify, sell and distribute this document is

View File

@@ -371,7 +371,7 @@ Betty
</pre>
<hr>
<p>Revised <!--webbot bot="Timestamp" s-type="EDITED" s-format="%d %b %Y" startspan -->08 Mar 2001<!--webbot bot="Timestamp" endspan i-checksum="14892" --></p>
<p>Revised <!--webbot bot="Timestamp" s-type="EDITED" s-format="%d %b %Y" startspan -->19 Aug 2001<!--webbot bot="Timestamp" endspan i-checksum="14767" --></p>
<p><EFBFBD> Copyright Jeremy Siek 2000. Permission to copy, use,
modify, sell and distribute this document is granted provided this copyright
notice appears in all copies. This document is provided &quot;as is&quot;

View File

@@ -312,7 +312,7 @@ simply use <tt>reverse_iterator_generator</tt> twice!<br><br>
<p>Revised
<!--webbot bot="Timestamp" s-type="EDITED" s-format="%d %b %Y" startspan -->08 Mar 2001<!--webbot bot="Timestamp" endspan i-checksum="14892" -->
<!--webbot bot="Timestamp" s-type="EDITED" s-format="%d %b %Y" startspan -->19 Aug 2001<!--webbot bot="Timestamp" endspan i-checksum="14767" -->
<p>&copy; Copyright Jeremy Siek 2000. Permission to copy, use, modify, sell

View File

@@ -23,7 +23,13 @@
<TT>tie</TT>
</H1>
<P>
<h3>
[This version of tie has been removed from the utility.hpp
header.&nbsp; There is a new, more general version of <a
href="../tuple/doc/tuple_users_guide.html#tiers">tie</a> in the Boost
Tuples Library. The more general version handles an (almost) arbitrary
number of arguments, instead of just two. The version in utility.hpp
had to be removed to avoid name clashes.]</h3>
<PRE>
template &lt;class A, class B&gt;
tied&lt;A,B&gt; tie(A&amp; a, B&amp; b);
@@ -124,7 +130,7 @@ The output is:
<TABLE>
<TR valign=top>
<TD nowrap>Copyright &copy 2000</TD><TD>
<A HREF=http://www.boost.org/people/jeremy_siek.htm>Jeremy Siek</A>,
<a HREF="../../people/jeremy_siek.htm">Jeremy Siek</a>,
Univ.of Notre Dame (<A
HREF="mailto:jsiek@lsc.nd.edu">jsiek@lsc.nd.edu</A>)<br>
<A HREF=http://www.lsc.nd.edu/~llee1>Lie-Quan Lee</A>, Univ.of Notre Dame (<A HREF="mailto:llee1@lsc.nd.edu">llee1@lsc.nd.edu</A>)<br>

View File

@@ -19,14 +19,16 @@
#include <set>
#include <algorithm>
#include <iostream>
#include <boost/utility.hpp>
// Note: tie() use to live in boost/utility.hpp, but
// not it is part of the more general Boost Tuple Library.
#include <boost/tuple/tuple.hpp>
int
main(int, char*[])
{
{
typedef std::set<int> SetT;
SetT::iterator i, end;
SetT::iterator i;
bool inserted;
int vals[5] = { 5, 2, 4, 9, 1 };

View File

@@ -1,75 +0,0 @@
# -*- makefile -*-
DVIPS = dvips
LATEX = pdflatex
LATEXOUT = pdf
RESULT = pdf
#LATEX = latex
#LATEXOUT = dvi
#RESULT = ps
.SUFFIXES: .tex .dvi .ps .pdf .c .lg .eps
.c.lg:
lgrind -i -o $*.lg -a -lc++ $*.c
.eps.pdf:
epstopdf $*.eps
.tex.pdf:
@ if test ! -f $*.ind; then echo "" > $*.ind; fi
@ $(LATEX) $*
@ if ( grep 'Writing index file' $*.log > /dev/null ); \
then makeindex $* ; $(LATEX) $* ; fi
@ if ( grep 'LaTeX Warning: Label(s) may' $*.log > /dev/null ); \
then $(LATEX) $* ; fi
@ if ( grep 'LaTeX Warning: Citation' $*.log > /dev/null ); \
then bibtex $* ; $(LATEX) $* ; fi
@ if ( grep 'LaTeX Warning: Label(s) may' $*.log > /dev/null ); \
then $(LATEX) $* ; fi
@ if ( grep 'LaTeX Warning: Label(s) may' $*.log > /dev/null ); \
then $(LATEX) $* ; fi
@ if ( grep 'LaTeX Warning: Label(s) may' $*.log > /dev/null ); \
then $(LATEX) $* ; fi
.dvi.ps:
$(DVIPS) -o $*.ps $*
.ps.pdf:
distill -v -maxsubsetpct 99 -subsetfonts on -pairs $*.ps $*.pdf
SRCCODE =
#
# Default rule
#
default: iter-adaptor.$(RESULT)
#
# LaTeX stuff
#
TEX = iter-adaptor.tex
iter-adaptor.dvi: $(TEX) $(SRCCODELG)
iter-adaptor.ps: iter-adaptor.dvi
iter-adaptor.pdf: $(PDFPICT) $(TEX) $(SRCCODELG)
dist: iter-adaptor.ps iter-adaptor.pdf
mkdir -p iter-adaptor
cp $(TEX) $(SRCCODELG) $(EPS) $(PS) \
iter-adaptor.bbl iter-adaptor.ps iter-adaptor.pdf \
iter-adaptor
tar cvf - ./iter-adaptor | gzip > iter-adaptor.tar.gz
#
# Standard rules
#
clean:
/bin/rm -f *.dvi *.o *.ps *.pdf *.log *.blg *.bbl *.aux *~ *.out *.ind

View File

@@ -1,36 +0,0 @@
\usepackage{times}
\newif\ifpdf
\ifx\pdfoutput\undefined
\pdffalse
\else
\pdfoutput=1
\pdftrue
\fi
\ifpdf
\usepackage[
pdftex,
colorlinks=true,
linkcolor=blue,filecolor=blue,pagecolor=blue,urlcolor=blue
]{hyperref}
\fi
\ifpdf
\newcommand{\concept}[1]{\hyperref[concept:#1]{\textsf{#1}}}
\newcommand{\stlconcept}[1]{\href{http://www.sgi.com/Technology/STL/#1.html}{\textsf{#1}}}
\newcommand{\link}[2]{\hyperref[#1]{#2}}
\else
\newcommand{\concept}[1]{\textsf{#1}}
\newcommand{\stlconcept}[1]{\textsf{#1}}
\newcommand{\href}[2]{#2}
\newcommand{\link}[2]{#2}
\fi
\newcommand{\code}[1]{{\small \texttt{#1}}}
\newcommand{\Note}[1]{\marginpar{\begin{flushleft}%
{%%\tiny %%\footnotesize
{\bf Note:} #1}%
\end{flushleft}}}

View File

@@ -1,423 +0,0 @@
% Introduction/Motivation, etc. (Dave & Jeremy)
% iterator policies (Dave)
% default policies
% type<> wrapper
% \cite{alexandrescu01:_modern_cpp_design}
% iterator_comparisons base (B&N) (Jeremy) \cite{Barton94}
% workaround for g++ compiler bug with friend functions?
% operator_array_proxy (Dave)
% default pointer/reference type selection (Dave)
% wrapping non-iterators (count_iterator) (Jeremy)
% named template parameters (Jeremy)
% operator[] return type (Dave)
% the static asserts (Dave)
% generators (Jeremy)
% type generators
% tempting to try to use inheritance to replace
% templated typedef, but that doesn't work.
% object generators
% const/non-const interoperability (Dave)
% implementing const/mutable iterators with the same class
% common mistake is to make the return type of operator*()
% depend on whether the iterator object is const/non-const.
% See the transform iterator in \cite{TMPW00:Weiser}
% custom iterators \cite{TMPW00:Baus}
% generating iterators
% line iterator \cite{austern99:_gener_progr_stl}
% constant iterator \cite{koenig97:_rumin_cpp}
% reverse iterator, front_insert_iterator, back_insert_iterator,
% insert_iterator \cite{iso98:_cpp_final_draft_standard}
% view iterators
% \cite{TMPW00:Weiser}
% future work, container adaptors
\documentclass{netobjectdays}
\input{defs}
\begin{document}
\title{Generating Iterator Types}
\author{David Abrahams$^\dag$ and Jeremy Siek$^\ddag$ \\
\\
$^\dag$ Altra Broadband \\
\texttt{abrahams@altrabroadband.com}\\
\\
$^\ddag$ Computer Science Department \\
Indiana University \\
Lindley Hall \\
150 S. Woodlawn Ave. \\
Bloomington, IN\ \ 47405-7104\\
\texttt{jsiek@cs.indiana.edu}
}
\maketitle
\begin{abstract}
The iterator abstraction is one of the most commonly used in
programming and a considerable amount of time is spent building new
iterator types. However, implementing an iterator type that satisfies
the C++ Standard requirements for an iterator can be
challenging. There are a number of common mistakes that people make,
and there are necessary complexities in a C++ Standard conforming
implementation that one would rather not have to think about. In this
paper we present the iterator type generator in the Boost Iterator
Adaptor Library. This generator simplifies the creation of iterators;
it automates the error-prone and redundant parts of the implementation
and greatly simplifies the creation of iterator types that are
variations on other iterators (creating iterator adaptors). The
design of the Iterator Adaptor Library is an example of policy-based
design, and the implementation employs template meta-programming.
\end{abstract}
\section{Introduction}
%- defaults make it easy to adapt an iterator
%- extensions from base operations to other operations make it
% easier to create iterators
Iterators play an important role in modern C++ programing. The
iterator is the central abstraction of the algorithms of the Standard
Library and creating new iterator types and adapting old ones are
common tasks for C++ programmers. There are plenty of examples of
custom-made iterators in the literature: the
\code{line\_iterator}~\cite{austern99:_gener_progr_stl},
\code{Constant\_iterator}~\cite{koenig97:_rumin_cpp},
\code{istream\_iterator} and
\code{ostream\_iterator}~\cite{iso98:_cpp_final_draft_standard} to
name a few. Also a growing number of generic iterator adaptors are
available: \code{Checked\_iter}~\cite{stroustrup00:_cpp_prog_lang},
iterators of the View Template Library~\cite{TMPW00:Weiser}, custom
and smart iterators~\cite{becker98:_smart_iteraters,TMPW00:Baus},
compound iterators~\cite{alexandrescu98:_compound_iters}, and several
iterators in the MTL~\cite{siek99:_scitools}.
For an iterator to be usable with the Standard algorithms (and other
generic algorithms in third-party libraries), it must fulfill the
Standard requirements for an iterator type, which range from the few
requirements of an \stlconcept{InputIterator} to the many requirements
of a \stlconcept{RandomAccessIterator}. Implementing an iterator class
that meets these requirements is a tedious and error-prone task
despite the fact that most iterators are conceptually simple.
\subsection{Redundant Operators}
Perhaps the most obvious of reasons that implementing an iterator can
be tediuos is that there are lots of redundant operators. That is,
there are many operators that can be trivially defined in terms of
other operators. For example, the \code{operator++(int)} is often best
implemented in terms of \code{operator++()} as the example below
shows.
{\footnotesize
\begin{verbatim}
class iter {
// ...
iter& operator++() { /* ... */ return *this; }
iter operator++(int) { iter tmp(*this); ++*this; return tmp; }
};
\end{verbatim}
}
For a full \stlconcept{RandomAccessIterator}, there are a total of 17
operators. 7 of the operators are fundamental while the other 10 are
redundant.
% 7 core operations
% 10 derived operations
% \code{operator->}
% \code{operator[]}
% \code{operator++(int)},
% \code{operator--(int)},
% \code{operator-=},
% \code{operator+},
% \code{operator!=},
% \code{operator>},
% \code{operator<=},
% \code{operator>=}
\subsection{Delagation of Operators for Iterator Adaptors}
It is often the case that an iterator adaptor changes the meaning of
one or two operators while leaving the rest of the operators defined
in the same way as the underlying iterator. This is typically
implemented with delegating functions. The following example shows an
excerpt from an \code{indirect\_iterator} adaptor, which takes an
iterator over pointers and creates an iterator over the things pointed
to. The \code{operator*} is changed to dereference twice but all the
other operators stay the same. Writing all of the delegating functions
for the \code{indirect\_iterator} would be a tedious task.
{\footnotesize
\begin{verbatim}
template <class Iterator> class indirect_iterator {
public:
// Adapt the meaning of dereference
reference operator*() const {
return **iter; // dereference twice
}
// Delegating the implementation to the underlying iterator.
iter_adaptor& operator++() { ++iter; return *this; }
iter_adaptor& operator--() { --iter; return *this; }
// delegate for all the other operators...
private:
Iterator iter;
};
\end{verbatim}
}
\subsection{Iterator Complexities}
In addition to the tedious aspects of iterator implementation, there
are some complexities that trip up even the most experienced of
programmers.
\subsubsection{Constant/Mutable Iterator Interactions}
One of the main situations in which iterators are used is inside
containers. These iterators usually come in pairs: a constant iterator
type and a mutable iterator type. It is desirable to allow the
constant and mutable iterators to interoperate in terms of their
binary operators. For example, suppose that you are implementing a
container type \code{C}. Then you ought to define the following four
version of \code{operator==}.
{\footnotesize
\begin{verbatim}
bool operator==(const C::iterator& x, const C::iterator& y);
bool operator==(const C::const_iterator& x, const C::iterator& y);
bool operator==(const C::iterator& x, const C::const_iterator& y);
bool operator==(const C::const_iterator& x, const C::const_iterator& y);
\end{verbatim}
}
Implementers often forget to define the operators for const/mutable
iterator interaction. In addition, iterator adaptors applied to these
kinds of iterators should propagate the ability to interact. For
example, a reverse iterator adaptor applied to \code{C::iterator} and
\code{C::const\_iterator} should result in reverse iterator types that
also have operators defined for the const/mutable interactions.
\subsubsection{Constant/Mutable Iterator Implementation}
Another subtlety in the implementation of iterators is how the the
distinction between constant and mutable iterators affects the
implementation. It is obvious that a constant iterator should have a
const \code{reference} type, while a mutable iterator should have a
non-const \code{reference}, though in other regards the constant and
mutable versions of an iterator are the same. It is therefore
desirable to implement both versions of the iterator with a single
class. It is possible to do this, however some care must be taken.
One common mistake is that the programmer will confuse the difference
between a const iterator object and a constant iterator. Such a
misunderstanding can, for example, lead to an iterator class that has
two versions of \code{operator*}, one that is a const member function
and one that is not.
{\footnotesize
\begin{verbatim}
// this is a mistake
reference operator*();
const_reference operator*() const;
\end{verbatim}
}
The right way to implement both a constant and mutable iterators using
the same class is to make the iterator a class template and make the
reference type a parameter. To create the constant iterator a const
reference would be used as the template argument and to create the
mutable iterator a non-const reference would be used as the template
argument. There should be only one \code{operator*} that returns the
\code{reference} type and the member function should be const since
dereferencing an iterator does not change the state of the iterator
object itself (unlike \code{operator++}).
{\footnotesize
\begin{verbatim}
// this is right
reference operator*() const;
\end{verbatim}
}
\subsubsection{Input Iterators and \code{operator->}}
When creating an iterator adaptor that can accept an
\stlconcept{InputIterator} as the adapted type some extra care must be
taken in the implementation of \code{operator->}. \Note{Dave fills in
the rest}
% Automatic implementation of redundant operators
% Default delegation to adapted iterator
% complexities:
% const-non const interaction
% const/mutable iterator distinction
% input iterator \code{operator->}
\section{The Boost \code{iterator\_adaptor}}
\subsection{Example}
It is often useful to automatically apply some function to the value
returned by dereferencing an iterator. The transform iterator of the
Iterator Adaptor Library makes it easy to create an iterator adaptor
which does just that. Here we will show how easy it is to implement
the transform iterator using the
\code{iterator\_adaptor} template.
We want to be able to adapt a range of iterators and functions, so the
policies class will have a template parameter for the function type
and it will have a data member of that type. We know that the function
takes one argument and that we'll need to be able to deduce the
\code{result\_type} of the function so we can use it for the adapted
iterator's \code{value\_type}. \stlconcept{AdaptableUnaryFunction} is
the \textsf{concept}\cite{austern99:_gener_progr_stl} that fulfills
those requirements.
To implement a transform iterator we will only change one of the base
iterator's behaviors, so the \code{transform\_iterator\_policies}
class can inherit the rest from \code{default\_iterator\_policies}. We
will define the \code{dereference()} member function, which is used
to implement \code{operator*()} of the adapted iterator. The
implementation will dereference the base iterator and apply the
function object. The \code{type<Reference>} parameter is used
to convey the appropriate return type. The complete code for
\code{transform\_iterator\_policies} is:
{\footnotesize
\begin{verbatim}
template <class AdaptableUnaryFunction>
struct transform_iterator_policies : public default_iterator_policies
{
transform_iterator_policies() { }
transform_iterator_policies(const AdaptableUnaryFunction& f)
: m_f(f) { }
template <class Reference, class BaseIterator>
Reference dereference(type<Reference>, const BaseIterator& i) const
{ return m_f(*i); }
AdaptableUnaryFunction m_f;
};
\end{verbatim}
}
The next step is to use the \code{iterator\_adaptor} template to
construct the transform iterator type. The nicest way to package the
construction of the transform iterator is to create a \emph{type
generator}, which is a class template whose sole purpose is to
simplify the instantiation of some other complicated class
template. It fulfills the same need as a templated typedef would if
that were part of the {C++} language.
The first template parameter to the generator will be the type of the
function object and the second will be the base iterator type. We use
\code{iterator\_adaptor} to define the transform iterator type as a
nested \code{typedef} inside the
\code{transform\_iterator\_generator} class. Because the function may
return by-value, we must limit the \code{iterator\_category} to
\stlconcept{InputIterator}, and the iterator's \code{reference} type cannot be a
true reference (the standard allows this for input iterators), so in
this case we can use few of \code{iterator\_adaptor}'s default template
arguments.
{\footnotesize
\begin{verbatim}
template <class AdaptableUnaryFunction, class Iterator>
struct transform_iterator_generator
{
typedef typename AdaptableUnaryFunction::result_type value_type;
public:
typedef iterator_adaptor<Iterator,
transform_iterator_policies<AdaptableUnaryFunction>,
value_type, value_type, value_type*, std::input_iterator_tag> type;
};
\end{verbatim}
}
As a finishing touch, we will create an
\textsf{object generator} for the transform iterator, which
is a function that makes it more convenient to create objects of some
class template.
{\footnotesize
\begin{verbatim}
template <class AdaptableUnaryFunction, class Iterator>
typename transform_iterator_generator<AdaptableUnaryFunction,
Iterator>::type
make_transform_iterator(Iterator base,
const AdaptableUnaryFunction& f = AdaptableUnaryFunction())
{
typedef typename transform_iterator_generator<AdaptableUnaryFunction,
Iterator>::type result_t;
return result_t(base, f);
}
\end{verbatim}
}
Here is an example that shows how to use a transform iterator to
iterate through a range of numbers, multiplying each of them by 2
and printing the result to standard output.
{\footnotesize
\begin{verbatim}
#include <functional>
#include <algorithm>
#include <iostream>
#include <boost/iterator_adaptors.hpp>
int main(int, char*[])
{
int x[] = { 1, 2, 3, 4, 5, 6, 7, 8 };
const int N = sizeof(x)/sizeof(int);
std::cout << "multiplying the array by 2:" << std::endl;
std::copy(boost::make_transform_iterator(x,
std::bind1st(std::multiplies<int>(), 2)),
boost::make_transform_iterator(x + N,
std::bind1st(std::multiplies<int>(), 2)),
std::ostream_iterator<int>(std::cout, " "));
std::cout << std::endl;
return 0;
}
\end{verbatim}
}
\noindent This output is:
{\footnotesize
\begin{verbatim}
2 4 6 8 10 12 14 16
\end{verbatim}
}
\bibliographystyle{abbrv}
\bibliography{refs,tmpw00}
\end{document}

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@@ -1,102 +0,0 @@
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@@ -1,94 +0,0 @@
@TechReport{stepa.lee-1994:the.s:TR,
author = "A. A. Stepanov and M. Lee",
title = "{The Standard Template Library}",
institution = "ISO Programming Language C++ Project",
year = "1994",
number = "X3J16/94-0095, WG21/N0482",
month = may,
}
@Book{ austern99:_gener_progr_stl,
author = "Matthew H. Austern",
title = "Generic Programming and the {STL}",
publisher = "Addison-Wesley",
year = 1999,
series = "Professional computing series"
}
@Book{koenig97:_rumin_cpp,
author = {Andrew Koenig and Barbara Moo},
title = {Ruminations on {C++}},
publisher = {Addison Wesley},
year = 1997
}
@Book{iso98:_cpp_final_draft_standard,
author = "International Organization for Standardization
(ISO)",
title = "ISO/IEC Final Draft International Standard 14882:
Programming Language C++",
year = 1998,
address = "1 rue de Varemb\'e, Case postale 56, CH-1211
Gen\`eve 20, Switzerland"
}
@Book{alexandrescu01:_modern_cpp_design,
author = {Andrei Alexandrescu},
title = {Modern {C++} Design},
publisher = {Addison Wesley},
year = 2001
}
@BOOK { Barton94,
AUTHOR = "John Barton and Lee Nackman",
TITLE = "Scientific and Engineering {C++}",
PUBLISHER = "Addison-Wesley",
YEAR = 1994
}
@Book{gamma95:_design_patterns,
author = {Erich Gamma and Richard Helm and Ralph Johnson and John Vlissides},
title = {Design Patterns: Elements of Reusable Object-Oriented Software},
publisher = {Addison-Welsey},
year = 1995,
series = {Professional Computing}
}
@Book{stroustrup00:_cpp_prog_lang,
author = {Bjarne Stroustrup},
title = {The {C++} Programming Language},
publisher = {Addison-Wesley},
year = 2000,
edition = {Special}
}
@Article{alexandrescu98:_compound_iters,
author = {Andrei Alexandrescu},
title = {Compound iterators of STL},
journal = {{C/C++} Users Journal},
year = 1998,
volume = 16,
number = 10,
pages = {79-82},
month = October
}
@Article{becker98:_smart_iteraters,
author = {Thomas Becker},
title = {Smart Iterators and STL},
journal = {{C/C++} Users Journal},
year = 1998,
volume = 16,
number = 9,
month = {September}
}
@InBook{siek99:_scitools,
author = {Jeremy G. Siek and Andrew Lumsdaine},
title = {Modern Software Tools for Scientific Computing},
chapter = {A Modern Framework for Portable High Performance
Numerical Linear Algebra},
publisher = {Birkhauser},
year = 1999,
}

View File

@@ -1,249 +0,0 @@
@InProceedings{TMPW00:Eisenecker,
AUTHOR = "Ulrich W. Eisenecker and Frank Blinn and Krzysztof Czarnecki",
TITLE = "A Solution to the Constructor-Problem of Mixin-Based Programming in {C++}",
BOOKTITLE = "First Workshop on {C++} Template Programming,
Erfurt, Germany",
MONTH = "October 10",
YEAR = "2000",
URL = "http://oonumerics.org/tmpw00/",
ABSTRACT =
"Mixin-Based Programming in C++ is a powerful programming style
based on the parameterized inheritance idiom and the composition
of C++ templates. Type expressions describing specific inheritance
hierarchies can be composed either automatically using generative
programming idioms in C++ or manually. Unfortunately, the mixin-based
C++ programming techniques published to date do not adequately support
optional and alternative mixin classes with constructors expecting
varying numbers of arguments, which are common in practice. This
is because the varying base class constructors do not provide a
uniform interface on which the constructors of the derived classes
could rely. This paper discusses several partial solutions to this
problem that were proposed to date and presents a new, complete
solution. The new solution uses generative programming techniques to
automatically generate the appropriate constructors, and this way it
avoids the overhead and clumsiness of instantiating composed mixin
classes in the client code using the partial solutions. In fact,
the new solution allows users to instantiate automatically composed
mixin classes with the simplicity of instantiating concrete classes
from traditional class hierarchies. Finally, the new solution does
not suffer from the scalability problems of the partial solutions."
}
@InProceedings{TMPW00:Berti,
AUTHOR = "Guntram Berti",
TITLE = "Generic Components for Grid Data Structures and Algorithms with {C++}",
BOOKTITLE = "First Workshop on {C++} Template Programming,
Erfurt, Germany",
MONTH = "October 10",
YEAR = "2000",
URL = "http://oonumerics.org/tmpw00/",
ABSTRACT =
"Grids are fundamental data structures for representing
geometric structures or their subdivisions. We propose a strategy
for decoupling algorithms working on grids from the details of
grid representations, using a generic programming approach in C++.
Functionality of grid data structures is captured by a small set of
primitives, divided into combinatorial and geometric ones. Special
attention is paid to the generic implementation of grid functions, which
correspond to the notion of mappings from grid elements (e. g. vertices)
to entities of a given type. Experiments indicate that the overhead
of the generic formulation is low and can be completely eliminated in
some cases."
}
@InProceedings{TMPW00:Veldhuizen,
AUTHOR = "Todd L. Veldhuizen",
TITLE = "Five compilation models for {C++} templates",
BOOKTITLE = "First Workshop on {C++} Template Programming,
Erfurt, Germany",
MONTH = "October 10",
YEAR = "2000",
URL = "http://oonumerics.org/tmpw00/",
ABSTRACT =
"This paper proposes an alternate structure for C++ compilers.
Type analysis is removed from the compiler and replaced with a
`type system library' which is treated as source code by the
compiler. Type computations are embedded in the intermediate
language of the compiler, and partial evaluation is used to drive
type analysis and template instantiation. By making simple changes to
the behavior of the partial evaluator, a wide range of compilation
models is achieved, each with a distinct tradeoff of compile time, code
size, and code speed. These models range from pure dynamic typing --
ideal for scripting C++ -- to profile-directed template instantiation.
This approach may solve several serious problems in compiling C++:
it achieves separate compilation of templates, allows template
code to be distributed in binary form by deferring template instantiation
until run time, and reduces the code bloat associated with
templates."
}
@InProceedings{TMPW00:Baus,
AUTHOR = "Christopher Baus and Thomas Becker",
TITLE = "Custom Iterators for the {STL}",
BOOKTITLE = "First Workshop on {C++} Template Programming,
Erfurt, Germany",
MONTH = "October 10",
YEAR = "2000",
URL = "http://oonumerics.org/tmpw00/",
ABSTRACT =
"We discuss several kinds of custom iterators for use with the STL
that are substantially different from the iterators that come with
the STL. We present class templates that implement these custom
iterators in a generic manner."
}
@InProceedings{TMPW00:Weiser,
AUTHOR = "Martin Weiser and Gary Powell",
TITLE = "The {View Template Library}",
BOOKTITLE = "First Workshop on {C++} Template Programming,
Erfurt, Germany",
MONTH = "October 10",
YEAR = "2000",
URL = "http://oonumerics.org/tmpw00/",
ABSTRACT =
"Views are container adaptors providing access to different
on the fly generated representations of the data in the container they
are applied to. The concept fits nicely into the framework defined by
the STL. This paper explains design, usage, and implementation of the
View Template Library, the currently most advanced implementation of
the views concept."
}
@InProceedings{TMPW00:Striegnitz,
AUTHOR = "J{\"o}rg Striegnitz and Stephen A. Smith",
TITLE = "An Expression Template aware Lambda Function",
BOOKTITLE = "First Workshop on {C++} Template Programming,
Erfurt, Germany",
MONTH = "October 10",
YEAR = "2000",
URL = "http://oonumerics.org/tmpw00/",
ABSTRACT =
"Template libraries such as the STL contain several generic algorithms
that expect functions as arguments and thereby cause frequent use of
function objects. User-defined function objects are awkward because
they must be declared as a class in namespace scope before they may
be used. In this paper, we describe a lambda function for C++, which
allows users to define function objects on the fly, without writing class
declarations. We show that, by using expression templates, the lambda
function can be implemented without hurting the runtime performance of a
program. Expression templates can also help to overcome the performance
penalties that may arise when using expressions over user-defined
types. Thus, we based our approach on PETE which is a framework
that simplifies the addition of expression template functionality to
user-defined classes."
}
@InProceedings{TMPW00:McNamara,
AUTHOR = "Brian McNamara and Yannis Smaragdakis",
TITLE = "Static Interfaces in {C++}",
BOOKTITLE = "First Workshop on {C++} Template Programming,
Erfurt, Germany",
MONTH = "October 10",
YEAR = "2000",
URL = "http://oonumerics.org/tmpw00/",
ABSTRACT =
"We present an extensible framework for defining and
using ``static interfaces'' in C++. Static interfaces are especially
useful as constraints on template parameters. That is, in addition to the
usual template $class T$, template definitions can specify that T ``isa''
Foo, for some static interface named Foo. These ``isa-constraints'' can be
based on either inheritance (named conformance: T publicly inherits Foo),
members (structural conformance: T has these member functions with these
signatures), or both. The constraint mechanism imposes no space or time
overheads at runtime; virtual functions are conspicuously absent from
our framework.
We demonstrate two key utilities of static interfaces. First,
constraints enable better error messages with template code. By applying
static interfaces as constraints, instantiating a template with the
wrong type is an error that can be caught at the instantiation point,
rather than later (typically in the bowels of the implementation).
Authors of template classes and template functions can also dispatch
``custom error messages'' to report named constraint violations by
clients, making debugging easier. We show examples of the improvement of
error messages when constraints are applied to STL code.
Second, constraints enable automatic compile-time dispatch of different
implementations of class or function templates based on the named
conformance properties of the template types. For example, $Set<T>$ can be
written to automatically choose the most efficient implementation: use a
hashtable implementation if ``T isa Hashable'', or else a binary search
tree if ``T isa LessThanComparable'' , or else a linked-list if merely ``T
isa EqualityComparable''. This dispatch can be completely hidden from
clients of Set, who just use $Set<T>$ as usual."
}
@InProceedings{TMPW00:Siek,
AUTHOR = "Jeremy Siek and Andrew Lumsdaine",
TITLE = "Concept Checking: Binding Parametric Polymorphism in {C++}",
BOOKTITLE = "First Workshop on {C++} Template Programming,
Erfurt, Germany",
MONTH = "October 10",
YEAR = "2000",
URL = "http://oonumerics.org/tmpw00/",
ABSTRACT =
"Generic programming in C++ is characterized by the use of template
parameters to represent abstract data types (or ``concepts'').
However, the C++ language itself does not provide a mechanism for
explicitly handling concepts. As a result, it can be difficult to
insure that a concrete type meets the requirements of the concept it
is supposed to represent. Error messages resulting from incorrect
use of a concrete type can be particularly difficult to decipher.
In this paper we present techniques to check parameters in generic
C++ libraries. Our techniques use standard C++ and introduce no
run-time overhead."
}
@InProceedings{TMPW00:Kuehl,
AUTHOR = "Dietmar K{\"u}hl",
TITLE = "{STL} and {OO} Don't Easily Mix",
BOOKTITLE = "First Workshop on {C++} Template Programming,
Erfurt, Germany",
MONTH = "October 10",
YEAR = "2000",
URL = "http://oonumerics.org/tmpw00/",
ABSTRACT =
"The STL is a powerful tool for many kinds of processing. Unfortunately,
using polymorphic objects with the STL seems not to work: Polymorphic
objects stored in STL containers either get sliced (i.e. only the base
part is copied or assigned but not the derived part) or, when storing
pointers to them instead, are not destroyed. Applying algorithms to
such containers often results in the wrong thing or complex predicate
objects are needed. This article shows how to overcome at least some
of these problems using some adaptors and also outlines a possible
implementation of STL for better integration with polymorphic objects.
The improved integration just acknowledges the distinction between the
object and the entity used to maintain it."
}
@InProceedings{TMPW00:Eichelberger,
AUTHOR = "H. Eichelberger and J. Wolff v. Gudenberg",
TITLE = "{UML} Description of the {STL}",
BOOKTITLE = "First Workshop on {C++} Template Programming,
Erfurt, Germany",
MONTH = "October 10",
YEAR = "2000",
URL = "http://oonumerics.org/tmpw00/eichelberger.pdf",
ABSTRACT =
"In this paper we show how the specification of the
Standard Template Library STL and its implementation can be described
by UML diagrams. We define appropriate stereotypes to
describe STL concepts like containers, iterators, function
objects and global algorithms. For the graphical description of the
implementation of the STL we extend the UML metamodel."
}

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@@ -211,7 +211,7 @@ iterator always returns by-value.
<hr>
<p>Revised <!--webbot bot="Timestamp" s-type="EDITED" s-format="%d %b %Y" startspan -->29 Mar 2001<!--webbot bot="Timestamp" endspan i-checksum="14896" --></p>
<p>Revised <!--webbot bot="Timestamp" s-type="EDITED" s-format="%d %b %Y" startspan -->19 Aug 2001<!--webbot bot="Timestamp" endspan i-checksum="14767" --></p>
<p><EFBFBD> Copyright Jeremy Siek 2000. Permission to copy, use,
modify, sell and distribute this document is granted provided this copyright
notice appears in all copies. This document is provided &quot;as is&quot;

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@@ -16,6 +16,8 @@
<h2>Contents</h2>
<ul>
<li>Class templates supporting the <a href="base_from_member.html">base-from-member
idiom</a></li>
<li>Function templates <a href="#checked_delete">checked_delete() and
checked_array_delete()</a></li>
<li>Function templates <a href="#functions next">next() and prior()</a></li>
@@ -131,11 +133,13 @@ emphasize that it is to be used only as a base class.&nbsp; Dave Abrahams notes
concern about the effect on compiler optimization of adding (even trivial inline)
destructor declarations. He says &quot;Probably this concern is misplaced, because
noncopyable will be used mostly for classes which own resources and thus have non-trivial destruction semantics.&quot;</p>
<h2>Class templates for the Base-from-Member Idiom</h2>
<p>See <a href="base_from_member.html">separate documentation</a>.</p>
<h2>Function template tie()</h2>
<p>See <a href="tie.html">separate documentation</a>.</p>
<hr>
<p>Revised&nbsp; <!--webbot bot="Timestamp" S-Type="EDITED" S-Format="%d %B, %Y" startspan
-->22 May, 2001<!--webbot bot="Timestamp" endspan i-checksum="13960"
-->10 September, 2001<!--webbot bot="Timestamp" endspan i-checksum="39328"
-->
</p>
<p><EFBFBD> Copyright boost.org 1999. Permission to copy, use, modify, sell and