Compare commits

..

5 Commits

Author SHA1 Message Date
Ralf W. Grosse-Kunstleve
09b13c55b2 Join ralf_grosse_kunstleve with HEAD
[SVN r9444]
2001-03-05 20:01:01 +00:00
nobody
aa26bc2137 This commit was manufactured by cvs2svn to create branch
'unlabeled-1.3.2'.

[SVN r9423]
2001-03-04 16:05:22 +00:00
nobody
f6533b3826 This commit was manufactured by cvs2svn to create branch
'unlabeled-1.3.2'.

[SVN r8778]
2001-01-27 11:31:59 +00:00
Jeremy Siek
e5c81d0702 fixed very strange VC++ bug that was showing up in graph/test/graph.cpp
Something about the code gen for compressed_pair_1::operator=
was going wrong. Writing it explicitly, and playing with some ordering
fixed the problem, don't ask my why.


[SVN r8765]
2001-01-25 04:45:52 +00:00
Dave Abrahams
6caf7d4d5a Initial checkin
[SVN r8757]
2001-01-24 18:36:52 +00:00
6 changed files with 819 additions and 795 deletions

View File

@@ -0,0 +1,53 @@
// (C) Copyright Jeremy Siek 2000. 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.
#include <boost/config.hpp>
#include <iostream>
#include <iterator>
#include <vector>
#include <boost/counting_iterator.hpp>
#include <boost/iterator_adaptors.hpp>
int main(int, char*[])
{
// Example of using counting_iterator_generator
std::cout << "counting from 0 to 4:" << std::endl;
boost::counting_iterator_generator<int>::type first(0), last(4);
std::copy(first, last, std::ostream_iterator<int>(std::cout, " "));
std::cout << std::endl;
// Example of using make_counting_iterator()
std::cout << "counting from -5 to 4:" << std::endl;
std::copy(boost::make_counting_iterator(-5),
boost::make_counting_iterator(5),
std::ostream_iterator<int>(std::cout, " "));
std::cout << std::endl;
// Example of using counting iterator to create an array of pointers.
const int N = 7;
std::vector<int> numbers;
// Fill "numbers" array with [0,N)
std::copy(boost::make_counting_iterator(0), boost::make_counting_iterator(N),
std::back_inserter(numbers));
std::vector<std::vector<int>::iterator> pointers;
// Use counting iterator to fill in the array of pointers.
std::copy(boost::make_counting_iterator(numbers.begin()),
boost::make_counting_iterator(numbers.end()),
std::back_inserter(pointers));
// Use indirect iterator to print out numbers by accessing
// them through the array of pointers.
std::cout << "indirectly printing out the numbers from 0 to "
<< N << std::endl;
std::copy(boost::make_indirect_iterator(pointers.begin()),
boost::make_indirect_iterator(pointers.end()),
std::ostream_iterator<int>(std::cout, " "));
std::cout << std::endl;
return 0;
}

View File

@@ -0,0 +1,428 @@
// (C) Copyright Steve Cleary, Beman Dawes, Howard Hinnant & John Maddock 2000.
// 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.
// compressed_pair: pair that "compresses" empty members
// (see libs/utility/compressed_pair.htm)
//
// JM changes 25 Jan 2000:
// Removed default arguments from compressed_pair_switch to get
// C++ Builder 4 to accept them
// rewriten swap to get gcc and C++ builder to compile.
// added partial specialisations for case T1 == T2 to avoid duplicate constructor defs.
#ifndef BOOST_DETAIL_COMPRESSED_PAIR_HPP
#define BOOST_DETAIL_COMPRESSED_PAIR_HPP
#include <algorithm>
#ifndef BOOST_OBJECT_TYPE_TRAITS_HPP
#include <boost/type_traits/object_traits.hpp>
#endif
#ifndef BOOST_SAME_TRAITS_HPP
#include <boost/type_traits/same_traits.hpp>
#endif
#ifndef BOOST_CALL_TRAITS_HPP
#include <boost/call_traits.hpp>
#endif
namespace boost
{
// compressed_pair
namespace details
{
// JM altered 26 Jan 2000:
template <class T1, class T2, bool IsSame, bool FirstEmpty, bool SecondEmpty>
struct compressed_pair_switch;
template <class T1, class T2>
struct compressed_pair_switch<T1, T2, false, false, false>
{static const int value = 0;};
template <class T1, class T2>
struct compressed_pair_switch<T1, T2, false, true, true>
{static const int value = 3;};
template <class T1, class T2>
struct compressed_pair_switch<T1, T2, false, true, false>
{static const int value = 1;};
template <class T1, class T2>
struct compressed_pair_switch<T1, T2, false, false, true>
{static const int value = 2;};
template <class T1, class T2>
struct compressed_pair_switch<T1, T2, true, true, true>
{static const int value = 4;};
template <class T1, class T2>
struct compressed_pair_switch<T1, T2, true, false, false>
{static const int value = 5;};
template <class T1, class T2, int Version> class compressed_pair_imp;
#ifdef __GNUC__
// workaround for GCC (JM):
using std::swap;
#endif
//
// can't call unqualified swap from within classname::swap
// as Koenig lookup rules will find only the classname::swap
// member function not the global declaration, so use cp_swap
// as a forwarding function (JM):
template <typename T>
inline void cp_swap(T& t1, T& t2)
{
#ifndef __GNUC__
using std::swap;
#endif
swap(t1, t2);
}
// 0 derive from neither
template <class T1, class T2>
class compressed_pair_imp<T1, T2, 0>
{
public:
typedef T1 first_type;
typedef T2 second_type;
typedef typename call_traits<first_type>::param_type first_param_type;
typedef typename call_traits<second_type>::param_type second_param_type;
typedef typename call_traits<first_type>::reference first_reference;
typedef typename call_traits<second_type>::reference second_reference;
typedef typename call_traits<first_type>::const_reference first_const_reference;
typedef typename call_traits<second_type>::const_reference second_const_reference;
compressed_pair_imp() {}
compressed_pair_imp(first_param_type x, second_param_type y)
: first_(x), second_(y) {}
explicit compressed_pair_imp(first_param_type x)
: first_(x) {}
explicit compressed_pair_imp(second_param_type y)
: second_(y) {}
first_reference first() {return first_;}
first_const_reference first() const {return first_;}
second_reference second() {return second_;}
second_const_reference second() const {return second_;}
void swap(compressed_pair_imp& y)
{
cp_swap(first_, y.first_);
cp_swap(second_, y.second_);
}
private:
first_type first_;
second_type second_;
};
// 1 derive from T1
template <class T1, class T2>
class compressed_pair_imp<T1, T2, 1>
: private T1
{
public:
typedef T1 first_type;
typedef T2 second_type;
typedef typename call_traits<first_type>::param_type first_param_type;
typedef typename call_traits<second_type>::param_type second_param_type;
typedef typename call_traits<first_type>::reference first_reference;
typedef typename call_traits<second_type>::reference second_reference;
typedef typename call_traits<first_type>::const_reference first_const_reference;
typedef typename call_traits<second_type>::const_reference second_const_reference;
compressed_pair_imp() {}
compressed_pair_imp(first_param_type x, second_param_type y)
: first_type(x), second_(y) {}
explicit compressed_pair_imp(first_param_type x)
: first_type(x) {}
explicit compressed_pair_imp(second_param_type y)
: second_(y) {}
first_reference first() {return *this;}
first_const_reference first() const {return *this;}
second_reference second() {return second_;}
second_const_reference second() const {return second_;}
void swap(compressed_pair_imp& y)
{
// no need to swap empty base class:
cp_swap(second_, y.second_);
}
private:
second_type second_;
};
// 2 derive from T2
template <class T1, class T2>
class compressed_pair_imp<T1, T2, 2>
: private T2
{
public:
typedef T1 first_type;
typedef T2 second_type;
typedef typename call_traits<first_type>::param_type first_param_type;
typedef typename call_traits<second_type>::param_type second_param_type;
typedef typename call_traits<first_type>::reference first_reference;
typedef typename call_traits<second_type>::reference second_reference;
typedef typename call_traits<first_type>::const_reference first_const_reference;
typedef typename call_traits<second_type>::const_reference second_const_reference;
compressed_pair_imp() {}
compressed_pair_imp(first_param_type x, second_param_type y)
: second_type(y), first_(x) {}
explicit compressed_pair_imp(first_param_type x)
: first_(x) {}
explicit compressed_pair_imp(second_param_type y)
: second_type(y) {}
first_reference first() {return first_;}
first_const_reference first() const {return first_;}
second_reference second() {return *this;}
second_const_reference second() const {return *this;}
void swap(compressed_pair_imp& y)
{
// no need to swap empty base class:
cp_swap(first_, y.first_);
}
private:
first_type first_;
};
// 3 derive from T1 and T2
template <class T1, class T2>
class compressed_pair_imp<T1, T2, 3>
: private T1,
private T2
{
public:
typedef T1 first_type;
typedef T2 second_type;
typedef typename call_traits<first_type>::param_type first_param_type;
typedef typename call_traits<second_type>::param_type second_param_type;
typedef typename call_traits<first_type>::reference first_reference;
typedef typename call_traits<second_type>::reference second_reference;
typedef typename call_traits<first_type>::const_reference first_const_reference;
typedef typename call_traits<second_type>::const_reference second_const_reference;
compressed_pair_imp() {}
compressed_pair_imp(first_param_type x, second_param_type y)
: first_type(x), second_type(y) {}
explicit compressed_pair_imp(first_param_type x)
: first_type(x) {}
explicit compressed_pair_imp(second_param_type y)
: second_type(y) {}
first_reference first() {return *this;}
first_const_reference first() const {return *this;}
second_reference second() {return *this;}
second_const_reference second() const {return *this;}
//
// no need to swap empty bases:
void swap(compressed_pair_imp&) {}
};
// JM
// 4 T1 == T2, T1 and T2 both empty
// Note does not actually store an instance of T2 at all -
// but reuses T1 base class for both first() and second().
template <class T1, class T2>
class compressed_pair_imp<T1, T2, 4>
: private T1
{
public:
typedef T1 first_type;
typedef T2 second_type;
typedef typename call_traits<first_type>::param_type first_param_type;
typedef typename call_traits<second_type>::param_type second_param_type;
typedef typename call_traits<first_type>::reference first_reference;
typedef typename call_traits<second_type>::reference second_reference;
typedef typename call_traits<first_type>::const_reference first_const_reference;
typedef typename call_traits<second_type>::const_reference second_const_reference;
compressed_pair_imp() {}
compressed_pair_imp(first_param_type x, second_param_type)
: first_type(x) {}
explicit compressed_pair_imp(first_param_type x)
: first_type(x) {}
first_reference first() {return *this;}
first_const_reference first() const {return *this;}
second_reference second() {return *this;}
second_const_reference second() const {return *this;}
void swap(compressed_pair_imp&) {}
private:
};
// 5 T1 == T2 and are not empty: //JM
template <class T1, class T2>
class compressed_pair_imp<T1, T2, 5>
{
public:
typedef T1 first_type;
typedef T2 second_type;
typedef typename call_traits<first_type>::param_type first_param_type;
typedef typename call_traits<second_type>::param_type second_param_type;
typedef typename call_traits<first_type>::reference first_reference;
typedef typename call_traits<second_type>::reference second_reference;
typedef typename call_traits<first_type>::const_reference first_const_reference;
typedef typename call_traits<second_type>::const_reference second_const_reference;
compressed_pair_imp() {}
compressed_pair_imp(first_param_type x, second_param_type y)
: first_(x), second_(y) {}
explicit compressed_pair_imp(first_param_type x)
: first_(x), second_(x) {}
first_reference first() {return first_;}
first_const_reference first() const {return first_;}
second_reference second() {return second_;}
second_const_reference second() const {return second_;}
void swap(compressed_pair_imp<T1, T2, 5>& y)
{
cp_swap(first_, y.first_);
cp_swap(second_, y.second_);
}
private:
first_type first_;
second_type second_;
};
} // details
template <class T1, class T2>
class compressed_pair
: private ::boost::details::compressed_pair_imp<T1, T2,
::boost::details::compressed_pair_switch<
T1,
T2,
::boost::is_same<typename remove_cv<T1>::type, typename remove_cv<T2>::type>::value,
::boost::is_empty<T1>::value,
::boost::is_empty<T2>::value>::value>
{
private:
typedef details::compressed_pair_imp<T1, T2,
::boost::details::compressed_pair_switch<
T1,
T2,
::boost::is_same<typename remove_cv<T1>::type, typename remove_cv<T2>::type>::value,
::boost::is_empty<T1>::value,
::boost::is_empty<T2>::value>::value> base;
public:
typedef T1 first_type;
typedef T2 second_type;
typedef typename call_traits<first_type>::param_type first_param_type;
typedef typename call_traits<second_type>::param_type second_param_type;
typedef typename call_traits<first_type>::reference first_reference;
typedef typename call_traits<second_type>::reference second_reference;
typedef typename call_traits<first_type>::const_reference first_const_reference;
typedef typename call_traits<second_type>::const_reference second_const_reference;
compressed_pair() : base() {}
compressed_pair(first_param_type x, second_param_type y) : base(x, y) {}
explicit compressed_pair(first_param_type x) : base(x) {}
explicit compressed_pair(second_param_type y) : base(y) {}
first_reference first() {return base::first();}
first_const_reference first() const {return base::first();}
second_reference second() {return base::second();}
second_const_reference second() const {return base::second();}
void swap(compressed_pair& y) { base::swap(y); }
};
// JM
// Partial specialisation for case where T1 == T2:
//
template <class T>
class compressed_pair<T, T>
: private details::compressed_pair_imp<T, T,
::boost::details::compressed_pair_switch<
T,
T,
::boost::is_same<typename remove_cv<T>::type, typename remove_cv<T>::type>::value,
::boost::is_empty<T>::value,
::boost::is_empty<T>::value>::value>
{
private:
typedef details::compressed_pair_imp<T, T,
::boost::details::compressed_pair_switch<
T,
T,
::boost::is_same<typename remove_cv<T>::type, typename remove_cv<T>::type>::value,
::boost::is_empty<T>::value,
::boost::is_empty<T>::value>::value> base;
public:
typedef T first_type;
typedef T second_type;
typedef typename call_traits<first_type>::param_type first_param_type;
typedef typename call_traits<second_type>::param_type second_param_type;
typedef typename call_traits<first_type>::reference first_reference;
typedef typename call_traits<second_type>::reference second_reference;
typedef typename call_traits<first_type>::const_reference first_const_reference;
typedef typename call_traits<second_type>::const_reference second_const_reference;
compressed_pair() : base() {}
compressed_pair(first_param_type x, second_param_type y) : base(x, y) {}
explicit compressed_pair(first_param_type x) : base(x) {}
first_reference first() {return base::first();}
first_const_reference first() const {return base::first();}
second_reference second() {return base::second();}
second_const_reference second() const {return base::second();}
void swap(compressed_pair& y) { base::swap(y); }
};
template <class T1, class T2>
inline
void
swap(compressed_pair<T1, T2>& x, compressed_pair<T1, T2>& y)
{
x.swap(y);
}
} // boost
#endif // BOOST_DETAIL_COMPRESSED_PAIR_HPP

View File

@@ -0,0 +1,128 @@
// (C) Copyright Steve Cleary, Beman Dawes, Howard Hinnant & John Maddock 2000.
// 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.
//
// Crippled version for crippled compilers:
// see libs/utility/call_traits.htm
//
/* Release notes:
01st October 2000:
Fixed call_traits on VC6, using "poor man's partial specialisation",
using ideas taken from "Generative programming" by Krzysztof Czarnecki
& Ulrich Eisenecker.
*/
#ifndef BOOST_OB_CALL_TRAITS_HPP
#define BOOST_OB_CALL_TRAITS_HPP
#ifndef BOOST_CONFIG_HPP
#include <boost/config.hpp>
#endif
#ifndef BOOST_ARITHMETIC_TYPE_TRAITS_HPP
#include <boost/type_traits/arithmetic_traits.hpp>
#endif
#ifndef BOOST_COMPOSITE_TYPE_TRAITS_HPP
#include <boost/type_traits/composite_traits.hpp>
#endif
namespace boost{
#if defined(BOOST_MSVC6_MEMBER_TEMPLATES) || !defined(BOOST_NO_MEMBER_TEMPLATES)
//
// use member templates to emulate
// partial specialisation:
//
namespace detail{
template <class T>
struct standard_call_traits
{
typedef T value_type;
typedef T& reference;
typedef const T& const_reference;
typedef const T& param_type;
};
template <class T>
struct simple_call_traits
{
typedef T value_type;
typedef T& reference;
typedef const T& const_reference;
typedef const T param_type;
};
template <class T>
struct reference_call_traits
{
typedef T value_type;
typedef T reference;
typedef T const_reference;
typedef T param_type;
};
template <bool simple, bool reference>
struct call_traits_chooser
{
template <class T>
struct rebind
{
typedef standard_call_traits<T> type;
};
};
template <>
struct call_traits_chooser<true, false>
{
template <class T>
struct rebind
{
typedef simple_call_traits<T> type;
};
};
template <>
struct call_traits_chooser<false, true>
{
template <class T>
struct rebind
{
typedef reference_call_traits<T> type;
};
};
} // namespace detail
template <typename T>
struct call_traits
{
private:
typedef detail::call_traits_chooser<(is_pointer<T>::value || is_arithmetic<T>::value) && sizeof(T) <= sizeof(void*), is_reference<T>::value> chooser;
typedef typename chooser::template rebind<T> bound_type;
typedef typename bound_type::type call_traits_type;
public:
typedef typename call_traits_type::value_type value_type;
typedef typename call_traits_type::reference reference;
typedef typename call_traits_type::const_reference const_reference;
typedef typename call_traits_type::param_type param_type;
};
#else
//
// sorry call_traits is completely non-functional
// blame your broken compiler:
//
template <typename T>
struct call_traits
{
typedef T value_type;
typedef T& reference;
typedef const T& const_reference;
typedef const T& param_type;
};
#endif // member templates
}
#endif // BOOST_OB_CALL_TRAITS_HPP

View File

@@ -1,464 +0,0 @@
// Demonstrate and test boost/operators.hpp on std::iterators -------------//
// (C) Copyright Jeremy Siek 1999. 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
// 04 Mar 01 Workaround for Borland (Dave Abrahams)
// 19 Feb 01 Take adavantage of improved iterator_traits to do more tests
// on MSVC. Hack around an MSVC-with-STLport internal compiler
// error. (David Abrahams)
// 11 Feb 01 Added test of operator-> for forward and input iterators.
// (Jeremy Siek)
// 11 Feb 01 Borland fixes (David Abrahams)
// 10 Feb 01 Use new adaptors interface. (David Abrahams)
// 10 Feb 01 Use new filter_ interface. (David Abrahams)
// 09 Feb 01 Use new reverse_ and indirect_ interfaces. Replace
// BOOST_NO_STD_ITERATOR_TRAITS with
// BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION to prove we've
// normalized to core compiler capabilities (David Abrahams)
// 08 Feb 01 Use Jeremy's new make_reverse_iterator form; add more
// comprehensive testing. Force-decay array function arguments to
// pointers.
// 07 Feb 01 Added tests for the make_xxx_iterator() helper functions.
// (Jeremy Siek)
// 07 Feb 01 Replaced use of xxx_pair_generator with xxx_generator where
// possible (which was all but the projection iterator).
// (Jeremy Siek)
// 06 Feb 01 Removed now-defaulted template arguments where possible
// Updated names to correspond to new generator naming convention.
// Added a trivial test for make_transform_iterator().
// Gave traits for const iterators a mutable value_type, per std.
// Resurrected my original tests for indirect iterators.
// (David Abrahams)
// 04 Feb 01 Fix for compilers without standard iterator_traits
// (David Abrahams)
// 13 Jun 00 Added const version of the iterator tests (Jeremy Siek)
// 12 Dec 99 Initial version with iterator operators (Jeremy Siek)
#include <boost/config.hpp>
#include <iostream>
#include <algorithm>
#include <functional>
#include <boost/iterator_adaptors.hpp>
#include <boost/pending/iterator_tests.hpp>
#include <boost/pending/integer_range.hpp>
#include <boost/concept_archetype.hpp>
#include <stdlib.h>
#include <vector>
#include <deque>
#include <set>
struct my_iterator_tag : public std::random_access_iterator_tag { };
using boost::dummyT;
struct my_iter_traits {
typedef dummyT value_type;
typedef dummyT* pointer;
typedef dummyT& reference;
typedef my_iterator_tag iterator_category;
typedef std::ptrdiff_t difference_type;
};
struct my_const_iter_traits {
typedef dummyT value_type;
typedef const dummyT* pointer;
typedef const dummyT& reference;
typedef my_iterator_tag iterator_category;
typedef std::ptrdiff_t difference_type;
};
typedef boost::iterator_adaptor<dummyT*,
boost::default_iterator_policies, dummyT> my_iterator;
typedef boost::iterator_adaptor<const dummyT*,
boost::default_iterator_policies, const dummyT> const_my_iterator;
struct mult_functor {
typedef int result_type;
typedef int argument_type;
// Functors used with transform_iterator must be
// DefaultConstructible, as the transform_iterator must be
// DefaultConstructible to satisfy the requirements for
// TrivialIterator.
mult_functor() { }
mult_functor(int aa) : a(aa) { }
int operator()(int b) const { return a * b; }
int a;
};
template <class Pair>
struct select1st_
: public std::unary_function<Pair, typename Pair::first_type>
{
const typename Pair::first_type& operator()(const Pair& x) const {
return x.first;
}
typename Pair::first_type& operator()(Pair& x) const {
return x.first;
}
};
struct one_or_four {
bool operator()(dummyT x) const {
return x.foo() == 1 || x.foo() == 4;
}
};
typedef std::deque<int> storage;
typedef std::deque<int*> pointer_deque;
typedef std::set<storage::iterator> iterator_set;
void more_indirect_iterator_tests()
{
// For some reason all heck breaks loose in the compiler under these conditions.
#if !defined(BOOST_MSVC) || !defined(__STL_DEBUG)
storage store(1000);
std::generate(store.begin(), store.end(), rand);
pointer_deque ptr_deque;
iterator_set iter_set;
for (storage::iterator p = store.begin(); p != store.end(); ++p)
{
ptr_deque.push_back(&*p);
iter_set.insert(p);
}
typedef boost::indirect_iterator_pair_generator<
pointer_deque::iterator
#ifdef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
, int
#endif
> IndirectDeque;
IndirectDeque::iterator db(ptr_deque.begin());
IndirectDeque::iterator de(ptr_deque.end());
assert(static_cast<std::size_t>(de - db) == store.size());
assert(db + store.size() == de);
IndirectDeque::const_iterator dci(db);
assert(db == dci);
assert(dci == db);
assert(dci != de);
assert(dci < de);
assert(dci <= de);
assert(de >= dci);
assert(de > dci);
dci = de;
assert(dci == de);
boost::random_access_iterator_test(db + 1, store.size() - 1, boost::next(store.begin()));
*db = 999;
assert(store.front() == 999);
typedef boost::indirect_iterator_generator<
iterator_set::iterator
#ifdef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
, int
#endif
>::type indirect_set_iterator;
typedef boost::indirect_iterator_generator<
iterator_set::iterator,
const int
>::type const_indirect_set_iterator;
indirect_set_iterator sb(iter_set.begin());
indirect_set_iterator se(iter_set.end());
const_indirect_set_iterator sci(iter_set.begin());
assert(sci == sb);
assert(sci != se);
sci = se;
assert(sci == se);
*boost::prior(se) = 888;
assert(store.back() == 888);
assert(std::equal(sb, se, store.begin()));
boost::bidirectional_iterator_test(boost::next(sb), store[1], store[2]);
assert(std::equal(db, de, store.begin()));
#endif
}
int
main()
{
dummyT array[] = { dummyT(0), dummyT(1), dummyT(2),
dummyT(3), dummyT(4), dummyT(5) };
const int N = sizeof(array)/sizeof(dummyT);
// sanity check, if this doesn't pass the test is buggy
boost::random_access_iterator_test(array,N,array);
// Check that the policy concept checks and the default policy
// implementation match up.
boost::function_requires<
boost::RandomAccessIteratorPoliciesConcept<
boost::default_iterator_policies, int*,
boost::iterator<std::random_access_iterator_tag, int, std::ptrdiff_t,
int*, int&>
> >();
// Test the iterator_adaptor
{
my_iterator i(array);
boost::random_access_iterator_test(i, N, array);
const_my_iterator j(array);
boost::random_access_iterator_test(j, N, array);
boost::const_nonconst_iterator_test(i, ++j);
}
// Test transform_iterator
{
int x[N], y[N];
for (int k = 0; k < N; ++k)
x[k] = k;
std::copy(x, x + N, y);
for (int k2 = 0; k2 < N; ++k2)
x[k2] = x[k2] * 2;
boost::transform_iterator_generator<mult_functor, int*>::type
i(y, mult_functor(2));
boost::input_iterator_test(i, x[0], x[1]);
boost::input_iterator_test(boost::make_transform_iterator(&y[0], mult_functor(2)), x[0], x[1]);
}
// Test indirect_iterator_generator
{
dummyT* ptr[N];
for (int k = 0; k < N; ++k)
ptr[k] = array + k;
typedef boost::indirect_iterator_generator<dummyT**
#ifdef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
, dummyT
#endif
>::type indirect_iterator;
typedef boost::indirect_iterator_generator<dummyT**, const dummyT>::type const_indirect_iterator;
indirect_iterator i(ptr);
boost::random_access_iterator_test(i, N, array);
#ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
boost::random_access_iterator_test(boost::make_indirect_iterator(ptr), N, array);
#endif
// check operator->
assert((*i).m_x == i->foo());
const_indirect_iterator j(ptr);
boost::random_access_iterator_test(j, N, array);
dummyT*const* const_ptr = ptr;
#ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
boost::random_access_iterator_test(boost::make_indirect_iterator(const_ptr), N, array);
#endif
boost::const_nonconst_iterator_test(i, ++j);
more_indirect_iterator_tests();
}
// Test projection_iterator_pair_generator
{
typedef std::pair<dummyT,dummyT> Pair;
Pair pair_array[N];
for (int k = 0; k < N; ++k)
pair_array[k].first = array[k];
typedef boost::projection_iterator_pair_generator<select1st_<Pair>,
Pair*, const Pair*
> Projection;
Projection::iterator i(pair_array);
boost::random_access_iterator_test(i, N, array);
boost::random_access_iterator_test(boost::make_projection_iterator(pair_array, select1st_<Pair>()), N, array);
boost::random_access_iterator_test(boost::make_projection_iterator< select1st_<Pair> >(pair_array), N, array);
Projection::const_iterator j(pair_array);
boost::random_access_iterator_test(j, N, array);
boost::random_access_iterator_test(boost::make_const_projection_iterator(pair_array, select1st_<Pair>()), N, array);
boost::random_access_iterator_test(boost::make_const_projection_iterator<select1st_<Pair> >(pair_array), N, array);
boost::const_nonconst_iterator_test(i, ++j);
}
// Test reverse_iterator_generator
{
dummyT reversed[N];
std::copy(array, array + N, reversed);
std::reverse(reversed, reversed + N);
typedef boost::reverse_iterator_generator<dummyT*
#ifdef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
, dummyT
#endif
>::type reverse_iterator;
reverse_iterator i(reversed + N);
boost::random_access_iterator_test(i, N, array);
#ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
boost::random_access_iterator_test(boost::make_reverse_iterator(reversed + N), N, array);
#endif
typedef boost::reverse_iterator_generator<const dummyT*
#ifdef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
, const dummyT
#endif
>::type const_reverse_iterator;
const_reverse_iterator j(reversed + N);
boost::random_access_iterator_test(j, N, array);
const dummyT* const_reversed = reversed;
#ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
boost::random_access_iterator_test(boost::make_reverse_iterator(const_reversed + N), N, array);
#endif
boost::const_nonconst_iterator_test(i, ++j);
}
// Test reverse_iterator_generator again, with traits fully deducible on all platforms
{
std::deque<dummyT> reversed_container;
std::reverse_copy(array, array + N, std::back_inserter(reversed_container));
const std::deque<dummyT>::iterator reversed = reversed_container.begin();
typedef boost::reverse_iterator_generator<
std::deque<dummyT>::iterator>::type reverse_iterator;
typedef boost::reverse_iterator_generator<
std::deque<dummyT>::const_iterator, const dummyT>::type const_reverse_iterator;
// MSVC/STLport gives an INTERNAL COMPILER ERROR when any computation
// (e.g. "reversed + N") is used in the constructor below.
const std::deque<dummyT>::iterator finish = reversed_container.end();
reverse_iterator i(finish);
boost::random_access_iterator_test(i, N, array);
boost::random_access_iterator_test(boost::make_reverse_iterator(reversed + N), N, array);
const_reverse_iterator j = reverse_iterator(finish);
boost::random_access_iterator_test(j, N, array);
const std::deque<dummyT>::const_iterator const_reversed = reversed;
boost::random_access_iterator_test(boost::make_reverse_iterator(const_reversed + N), N, array);
// Many compilers' builtin deque iterators don't interoperate well, though
// STLport fixes that problem.
#if defined(__SGI_STL_PORT) || !defined(__GNUC__) && !defined(__BORLANDC__) && !defined(BOOST_MSVC)
boost::const_nonconst_iterator_test(i, ++j);
#endif
}
// Test integer_range's iterators
{
int int_array[] = { 0, 1, 2, 3, 4, 5 };
boost::integer_range<int> r(0, 5);
boost::random_access_iterator_test(r.begin(), r.size(), int_array);
}
// Test filter iterator
{
// Using typedefs for filter_gen::type and filter_gen::policies_type
// confused Borland terribly.
typedef boost::detail::non_bidirectional_category<dummyT*>::type category;
typedef ::boost::filter_iterator_generator<one_or_four, dummyT*
#ifdef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
, dummyT
#endif
> filter_iter_gen;
#ifndef __BORLANDC__
typedef filter_iter_gen::type filter_iter;
#else
# define filter_iter filter_iter_gen::type // Borland has a problem with the above
#endif
filter_iter i(array, filter_iter::policies_type(one_or_four(), array + N));
boost::forward_iterator_test(i, dummyT(1), dummyT(4));
enum { is_forward = boost::is_same<
filter_iter::iterator_category,
std::forward_iterator_tag>::value };
BOOST_STATIC_ASSERT(is_forward);
// On compilers not supporting partial specialization, we can do more type
// deduction with deque iterators than with pointers... unless the library
// is broken ;-(
#if !defined(BOOST_MSVC) || defined(__SGI_STL_PORT)
std::deque<dummyT> array2;
std::copy(array+0, array+N, std::back_inserter(array2));
boost::forward_iterator_test(
boost::make_filter_iterator(array2.begin(), array2.end(), one_or_four()),
dummyT(1), dummyT(4));
boost::forward_iterator_test(
boost::make_filter_iterator<one_or_four>(array2.begin(), array2.end()),
dummyT(1), dummyT(4));
#endif
#if !defined(BOOST_MSVC) // This just freaks MSVC out completely
boost::forward_iterator_test(
boost::make_filter_iterator<one_or_four>(
boost::make_reverse_iterator(array2.end()),
boost::make_reverse_iterator(array2.begin())
),
dummyT(4), dummyT(1));
#endif
#ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
boost::forward_iterator_test(
boost::make_filter_iterator(array+0, array+N, one_or_four()),
dummyT(1), dummyT(4));
boost::forward_iterator_test(
boost::make_filter_iterator<one_or_four>(array, array + N),
dummyT(1), dummyT(4));
#endif
}
// check operator-> with a forward iterator
{
boost::forward_iterator_archetype<dummyT> forward_iter;
typedef boost::iterator_adaptor<boost::forward_iterator_archetype<dummyT>,
boost::default_iterator_policies,
dummyT, const dummyT&, const dummyT*,
std::forward_iterator_tag, std::ptrdiff_t> adaptor_type;
adaptor_type i(forward_iter);
if (0) // don't do this, just make sure it compiles
assert((*i).m_x == i->foo());
}
// check operator-> with an input iterator
{
boost::input_iterator_archetype<dummyT> input_iter;
typedef boost::iterator_adaptor<boost::input_iterator_archetype<dummyT>,
boost::default_iterator_policies,
dummyT, const dummyT&, const dummyT*,
std::input_iterator_tag, std::ptrdiff_t> adaptor_type;
adaptor_type i(input_iter);
if (0) // don't do this, just make sure it compiles
assert((*i).m_x == i->foo());
}
std::cout << "test successful " << std::endl;
return 0;
}

210
iterator_traits_test.cpp Normal file
View File

@@ -0,0 +1,210 @@
// (C) Copyright David Abrahams 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
// 04 Mar 2001 Patches for Intel C++ (Dave Abrahams)
// 19 Feb 2001 Take advantage of improved iterator_traits to do more tests
// on MSVC. Reordered some #ifdefs for coherency.
// (David Abrahams)
// 13 Feb 2001 Test new VC6 workarounds (David Abrahams)
// 11 Feb 2001 Final fixes for Borland (David Abrahams)
// 11 Feb 2001 Some fixes for Borland get it closer on that compiler
// (David Abrahams)
// 07 Feb 2001 More comprehensive testing; factored out static tests for
// better reuse (David Abrahams)
// 21 Jan 2001 Quick fix to my_iterator, which wasn't returning a
// reference type from operator* (David Abrahams)
// 19 Jan 2001 Initial version with iterator operators (David Abrahams)
#include <boost/detail/iterator.hpp>
#include <boost/type_traits.hpp>
#include <boost/operators.hpp>
#include <boost/static_assert.hpp>
#include <iterator>
#include <vector>
#include <list>
#include <cassert>
#include <iostream>
// An iterator for which we can get traits.
struct my_iterator1
: boost::forward_iterator_helper<my_iterator1, char, long, const char*, const char&>
{
my_iterator1(const char* p) : m_p(p) {}
bool operator==(const my_iterator1& rhs) const
{ return this->m_p == rhs.m_p; }
my_iterator1& operator++() { ++this->m_p; return *this; }
const char& operator*() { return *m_p; }
private:
const char* m_p;
};
// Used to prove that we don't require std::iterator<> in the hierarchy under
// MSVC6, and that we can compute all the traits for a standard-conforming UDT
// iterator.
struct my_iterator2
: boost::equality_comparable<my_iterator2
, boost::incrementable<my_iterator2
, boost::dereferenceable<my_iterator2,const char*> > >
{
typedef char value_type;
typedef long difference_type;
typedef const char* pointer;
typedef const char& reference;
typedef std::forward_iterator_tag iterator_category;
my_iterator2(const char* p) : m_p(p) {}
bool operator==(const my_iterator2& rhs) const
{ return this->m_p == rhs.m_p; }
my_iterator2& operator++() { ++this->m_p; return *this; }
const char& operator*() { return *m_p; }
private:
const char* m_p;
};
// Used to prove that we're not overly confused by the existence of
// std::iterator<> in the hierarchy under MSVC6 - we should find that
// boost::detail::iterator_traits<my_iterator3>::difference_type is int.
struct my_iterator3 : my_iterator1
{
typedef int difference_type;
my_iterator3(const char* p) : my_iterator1(p) {}
};
template <class Iterator,
class value_type, class difference_type, class pointer, class reference, class category>
struct non_portable_tests
{
// Unfortunately, the VC6 standard library doesn't supply these :(
BOOST_STATIC_ASSERT((
boost::is_same<
typename boost::detail::iterator_traits<Iterator>::pointer,
pointer
>::value));
BOOST_STATIC_ASSERT((
boost::is_same<
typename boost::detail::iterator_traits<Iterator>::reference,
reference
>::value));
};
template <class Iterator,
class value_type, class difference_type, class pointer, class reference, class category>
struct portable_tests
{
BOOST_STATIC_ASSERT((
boost::is_same<
typename boost::detail::iterator_traits<Iterator>::difference_type,
difference_type
>::value));
BOOST_STATIC_ASSERT((
boost::is_same<
typename boost::detail::iterator_traits<Iterator>::iterator_category,
category
>::value));
};
// Test iterator_traits
template <class Iterator,
class value_type, class difference_type, class pointer, class reference, class category>
struct input_iterator_test
: portable_tests<Iterator,value_type,difference_type,pointer,reference,category>
{
BOOST_STATIC_ASSERT((
boost::is_same<
typename boost::detail::iterator_traits<Iterator>::value_type,
value_type
>::value));
};
template <class Iterator,
class value_type, class difference_type, class pointer, class reference, class category>
struct non_pointer_test
: input_iterator_test<Iterator,value_type,difference_type,pointer,reference,category>
, non_portable_tests<Iterator,value_type,difference_type,pointer,reference,category>
{
};
template <class Iterator,
class value_type, class difference_type, class pointer, class reference, class category>
struct maybe_pointer_test
: portable_tests<Iterator,value_type,difference_type,pointer,reference,category>
#ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
, non_portable_tests<Iterator,value_type,difference_type,pointer,reference,category>
#endif
{
};
input_iterator_test<std::istream_iterator<int>, int, std::ptrdiff_t, int*, int&, std::input_iterator_tag>
istream_iterator_test;
//
#if defined(__BORLANDC__) && !defined(__SGI_STL_PORT)
typedef ::std::char_traits<char>::off_type distance;
non_pointer_test<std::ostream_iterator<int>,int,
distance,int*,int&,std::output_iterator_tag> ostream_iterator_test;
#elif defined(BOOST_MSVC_STD_ITERATOR)
non_pointer_test<std::ostream_iterator<int>,
int, void, void, void, std::output_iterator_tag>
ostream_iterator_test;
#else
non_pointer_test<std::ostream_iterator<int>,
void, void, void, void, std::output_iterator_tag>
ostream_iterator_test;
#endif
#ifdef __KCC
typedef long std_list_diff_type;
#else
typedef std::ptrdiff_t std_list_diff_type;
#endif
non_pointer_test<std::list<int>::iterator, int, std_list_diff_type, int*, int&, std::bidirectional_iterator_tag>
list_iterator_test;
maybe_pointer_test<std::vector<int>::iterator, int, std::ptrdiff_t, int*, int&, std::random_access_iterator_tag>
vector_iterator_test;
maybe_pointer_test<int*, int, std::ptrdiff_t, int*, int&, std::random_access_iterator_tag>
int_pointer_test;
non_pointer_test<my_iterator1, char, long, const char*, const char&, std::forward_iterator_tag>
my_iterator1_test;
non_pointer_test<my_iterator2, char, long, const char*, const char&, std::forward_iterator_tag>
my_iterator2_test;
non_pointer_test<my_iterator3, char, int, const char*, const char&, std::forward_iterator_tag>
my_iterator3_test;
int main()
{
char chars[100];
int ints[100];
for (std::ptrdiff_t length = 3; length < 100; length += length / 3)
{
std::list<int> l(length);
assert(boost::detail::distance(l.begin(), l.end()) == length);
std::vector<int> v(length);
assert(boost::detail::distance(v.begin(), v.end()) == length);
assert(boost::detail::distance(&ints[0], ints + length) == length);
assert(boost::detail::distance(my_iterator1(chars), my_iterator1(chars + length)) == length);
assert(boost::detail::distance(my_iterator2(chars), my_iterator2(chars + length)) == length);
assert(boost::detail::distance(my_iterator3(chars), my_iterator3(chars + length)) == length);
}
return 0;
}

View File

@@ -1,331 +0,0 @@
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 3.2//EN">
<html>
<head>
<meta name="generator" content="HTML Tidy, see www.w3.org">
<meta http-equiv="Content-Type" content="text/html; charset=windows-1252">
<meta name="GENERATOR" content="Microsoft FrontPage 4.0">
<meta name="ProgId" content="FrontPage.Editor.Document">
<title>Reverse Iterator Adaptor Documentation</title>
</head>
<body bgcolor="#FFFFFF" text="#000000">
<img src="../../c++boost.gif" alt="c++boost.gif (8819 bytes)" align=
"center" width="277" height="86">
<h1>Reverse Iterator Adaptor</h1>
Defined in header <a href=
"../../boost/iterator_adaptors.hpp">boost/iterator_adaptors.hpp</a>
<p>The reverse iterator adaptor flips the direction of a base iterator's
motion. Invoking <tt>operator++()</tt> moves the base iterator backward and
invoking <tt>operator--()</tt> moves the base iterator forward. The Boost
reverse iterator adaptor is better to use than the
<tt>std::reverse_iterator</tt> class in situations where pairs of
mutable/constant iterators are needed (e.g., in containers) because
comparisons and conversions between the mutable and const versions are
implemented correctly.
<h2>Synopsis</h2>
<pre>
namespace boost {
template &lt;class <a href=
"http://www.sgi.com/tech/stl/BidirectionalIterator.html">BidirectionalIterator</a>,
class Value, class Reference, class Pointer, class Category, class Distance&gt;
struct reverse_iterator_generator;
template &lt;class <a href=
"http://www.sgi.com/tech/stl/BidirectionalIterator.html">BidirectionalIterator</a>&gt;
typename reverse_iterator_generator&lt;BidirectionalIterator&gt;::type
make_reverse_iterator(BidirectionalIterator base)
}
</pre>
<hr>
<h2><a name="reverse_iterator_generator">The Reverse Iterator Type
Generator</a></h2>
The <tt>reverse_iterator_generator</tt> template is a <a href=
"../../more/generic_programming.html#type_generator">generator</a> of
reverse iterator types. The main template parameter for this class is the
base <tt>BidirectionalIterator</tt> type that is being adapted. In most
cases the associated types of the base iterator can be deduced using
<tt>std::iterator_traits</tt>, but in some situations the user may want to
override these types, so there are also template parameters for the base
iterator's associated types.
<blockquote>
<pre>
template &lt;class <a href=
"http://www.sgi.com/tech/stl/BidirectionalIterator.html">BidirectionalIterator</a>,
class Value, class Reference, class Pointer, class Category, class Distance&gt;
class reverse_iterator_generator
{
public:
typedef <tt><a href=
"./iterator_adaptors.htm#iterator_adaptor">iterator_adaptor</a>&lt;...&gt;</tt> type; // the resulting reverse iterator type
};
</pre>
</blockquote>
<h3>Example</h3>
In this example we sort a sequence of letters and then output the sequence
in descending order using reverse iterators.
<blockquote>
<pre>
#include &lt;boost/config.hpp&gt;
#include &lt;iostream&gt;
#include &lt;algorithm&gt;
#include &lt;boost/iterator_adaptors.hpp&gt;
int main(int, char*[])
{
char letters[] = "hello world!";
const int N = sizeof(letters)/sizeof(char) - 1;
std::cout &lt;&lt; "original sequence of letters:\t"
&lt;&lt; letters &lt;&lt; std::endl;
std::sort(letters, letters + N);
// Use reverse_iterator_generator to print a sequence
// of letters in reverse order.
boost::reverse_iterator_generator&lt;char*&gt;::type
reverse_letters_first(letters + N),
reverse_letters_last(letters);
std::cout &lt;&lt; "letters in descending order:\t";
std::copy(reverse_letters_first, reverse_letters_last,
std::ostream_iterator&lt;char&gt;(std::cout));
std::cout &lt;&lt; std::endl;
// to be continued...
</pre>
</blockquote>
The output is:
<blockquote>
<pre>
original sequence of letters: hello world!
letters in descending order: wroolllhed!
</pre>
</blockquote>
<h3>Template Parameters</h3>
<table border>
<tr>
<th>Parameter
<th>Description
<tr>
<td><tt><a href=
"http://www.sgi.com/tech/stl/BidirectionalIterator.html">BidirectionalIterator</a></tt>
<td>The iterator type being wrapped.
<tr>
<td><tt>Value</tt>
<td>The value-type of the base iterator and the resulting reverse
iterator.<br>
<b>Default:</b><tt>std::iterator_traits&lt;BidirectionalIterator&gt;::value_type</tt>
<tr>
<td><tt>Reference</tt>
<td>The <tt>reference</tt> type of the resulting iterator, and in
particular, the result type of <tt>operator*()</tt>.<br>
<b>Default:</b> If <tt>Value</tt> is supplied, <tt>Value&amp;</tt> is
used. Otherwise
<tt>std::iterator_traits&lt;BidirectionalIterator&gt;::reference</tt>
is used.
<tr>
<td><tt>Pointer</tt>
<td>The <tt>pointer</tt> type of the resulting iterator, and in
particular, the result type of <tt>operator-&gt;()</tt>.<br>
<b>Default:</b> If <tt>Value</tt> was supplied, then <tt>Value*</tt>,
otherwise
<tt>std::iterator_traits&lt;BidirectionalIterator&gt;::pointer</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;BidirectionalIterator&gt;::iterator_category</tt>
<tr>
<td><tt>Distance</tt>
<td>The <tt>difference_type</tt> for the resulting iterator.<br>
<b>Default:</b>
<tt>std::iterator_traits&lt;BidirectionalIterator&amp;gt::difference_type</tt>
</table>
<h3>Concept Model</h3>
The indirect iterator will model whichever <a href=
"http://www.sgi.com/tech/stl/Iterators.html">standard iterator concept
category</a> is modeled by the base iterator. Thus, if the base iterator is
a model of <a href=
"http://www.sgi.com/tech/stl/RandomAccessIterator.html">Random Access
Iterator</a> then so is the resulting indirect iterator. If the base
iterator models a more restrictive concept, the resulting indirect iterator
will model the same concept. The base iterator must be at least a <a href=
"http://www.sgi.com/tech/stl/BidirectionalIterator.html">Bidirectional
Iterator</a>
<h3>Members</h3>
The reverse iterator type implements the member functions and operators
required of the <a href=
"http://www.sgi.com/tech/stl/RandomAccessIterator.html">Random Access
Iterator</a> concept. In addition it has the following constructor:
<blockquote>
<pre>
reverse_iterator_generator::type(const BidirectionalIterator&amp; it)
</pre>
</blockquote>
<br>
<br>
<hr>
<p>
<h2><a name="make_reverse_iterator">The Reverse Iterator Object
Generator</a></h2>
The <tt>make_reverse_iterator()</tt> function provides a more convenient
way to create reverse iterator objects. The function saves the user the
trouble of explicitly writing out the iterator types.
<blockquote>
<pre>
template &lt;class BidirectionalIterator&gt;
typename reverse_iterator_generator&lt;BidirectionalIterator&gt;::type
make_reverse_iterator(BidirectionalIterator base);
</pre>
</blockquote>
<h3>Example</h3>
In this part of the example we use <tt>make_reverse_iterator()</tt> to
print the sequence of letters in reverse-reverse order, which is the
original order.
<blockquote>
<pre>
// continuing from the previous example...
std::cout &lt;&lt; "letters in ascending order:\t";
std::copy(boost::make_reverse_iterator(reverse_letters_last),
boost::make_reverse_iterator(reverse_letters_first),
std::ostream_iterator&lt;char&gt;(std::cout));
std::cout &lt;&lt; std::endl;
return 0;
}
</pre>
</blockquote>
The output is:
<blockquote>
<pre>
letters in ascending order: !dehllloorw
</pre>
</blockquote>
<hr>
<h2><a name="interactions">Constant/Mutable Iterator Interactions</a></h2>
<p>One failing of the standard <tt><a
href="http://www.sgi.com/tech/stl/ReverseIterator.html">reverse_iterator</a></tt>
adaptor is that it doesn't properly support interactions between adapted
<tt>const</tt> and non-<tt>const</tt> iterators. For example:
<blockquote>
<pre>
#include &lt;vector&gt;
template &lt;class T&gt; void convert(T x) {}
// Test interactions of a matched pair of random access iterators
template &lt;class Iterator, class ConstIterator&gt;
void test_interactions(Iterator i, ConstIterator ci)
{
bool eq = i == ci; // comparisons
bool ne = i != ci;
bool lt = i &lt; ci;
bool le = i &lt;= ci;
bool gt = i &gt; ci;
bool ge = i &gt;= ci;
std::size_t distance = i - ci; // difference
ci = i; // assignment
ConstIterator ci2(i); // construction
convert&lt;ConstIterator&gt;(i); // implicit conversion
}
void f()
{
typedef std::vector&lt;int&gt; vec;
vec v;
const vec&amp; cv;
test_interactions(v.begin(), cv.begin()); // <font color="#007F00">OK</font>
test_interactions(v.rbegin(), cv.rbegin()); // <font color="#FF0000">ERRORS ON EVERY TEST!!</font>
</pre>
</blockquote>
Reverse iterators created with <tt>boost::reverse_iterator_generator</tt> don't have this problem, though:
<blockquote>
<pre>
typedef boost::reverse_iterator_generator&lt;vec::iterator&gt;::type ri;
typedef boost::reverse_iterator_generator&lt;vec::const_iterator&gt;::type cri;
test_interactions(ri(v.begin()), cri(cv.begin())); // <font color="#007F00">OK!!</font>
</pre>
</blockquote>
Or, more simply,
<blockquote>
<pre>
test_interactions(
boost::make_reverse_iterator(v.begin()),
boost::make_reverse_iterator(cv.begin())); // <font color="#007F00">OK!!</font>
}
</pre>
</blockquote>
<p>If you are wondering why there is no
<tt>reverse_iterator_pair_generator</tt> in the manner of <tt><a
href="projection_iterator.htm#projection_iterator_pair_generator">projection_iterator_pair_generator</a></tt>,
the answer is simple: we tried it, but found that in practice it took
<i>more</i> typing to use <tt>reverse_iterator_pair_generator</tt> than to
simply use <tt>reverse_iterator_generator</tt> twice!<br><br>
<hr>
<p>Revised
<!--webbot bot="Timestamp" s-type="EDITED" s-format="%d %b %Y" startspan -->26 Feb 2001<!--webbot bot="Timestamp" endspan i-checksum="14386" -->
<p>&copy; 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 "as is" without express or
implied warranty, and with no claim as to its suitability for any purpose.
<!-- LocalWords: html charset alt gif hpp BidirectionalIterator const namespace struct
-->
<!-- LocalWords: ConstPointer ConstReference typename iostream int abcdefg
-->
<!-- LocalWords: sizeof PairGen pre Siek wroolllhed dehllloorw
-->
</body>
</html>