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various changes, almost forgot to check in

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[SVN r8379]
This commit is contained in:
Jeremy Siek
2000-12-03 06:20:23 +00:00
parent 04c0c043e0
commit 3852c810f3
1 changed files with 37 additions and 12 deletions
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49
include/boost/pending/iterator_adaptors.hpp
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@ -37,22 +37,23 @@ struct type {};
struct default_iterator_policies
{
// Some of these members were defined static, but Borland got confused
// and thought they were non-const.
// and thought they were non-const. Also, Sun C++ does not like static
// function templates.
template <class Reference, class Iterator>
Reference dereference(type<Reference>, const Iterator& x) const
{ return *x; }
template <class Iterator>
static void increment(Iterator& x)
void increment(Iterator& x)
{ ++x; }
template <class Iterator>
static void decrement(Iterator& x)
void decrement(Iterator& x)
{ --x; }
template <class Iterator, class DifferenceType>
static void advance(Iterator& x, DifferenceType n)
void advance(Iterator& x, DifferenceType n)
{ x += n; }
template <class Difference, class Iterator1, class Iterator2>
@ -350,6 +351,9 @@ public:
//=============================================================================
// Transform Iterator Adaptor
//
// Upon deference, apply some unary function object and return the
// result by value.
template <class AdaptableUnaryFunction>
struct transform_iterator_policies : public default_iterator_policies
@ -358,8 +362,8 @@ struct transform_iterator_policies : public default_iterator_policies
transform_iterator_policies(const AdaptableUnaryFunction& f) : m_f(f) { }
template <class Reference, class Iterator>
Reference dereference(type<Reference>, const Iterator& x) const
{ return m_f(*x); }
Reference dereference(type<Reference>, const Iterator& iter) const
{ return m_f(*iter); }
AdaptableUnaryFunction m_f;
};
@ -394,7 +398,16 @@ struct transform_iterator
//=============================================================================
// Indirect Iterators Adaptor
// Tried implementing this with transform_iterator, but that required
// Given a pointer to pointers (or iterator to iterators),
// apply a double dereference inside operator*().
//
// We use the term "outer" to refer to the first level iterator type
// and "inner" to refer to the second level iterator type. For
// example, given T**, T* is the inner iterator type and T** is the
// outer iterator type. Also, const T* would be the const inner
// iterator.
// We tried to implement this with transform_iterator, but that required
// using boost::remove_ref, which is not compiler portable.
struct indirect_iterator_policies : public default_iterator_policies
@ -422,7 +435,9 @@ struct indirect_traits
typedef typename OuterTraits::iterator_category iterator_category;
};
template <class OuterIterator, class InnerIterator,
template <class OuterIterator, // Mutable or Immutable, does not matter
class InnerIterator, // Mutable -> mutable indirect iterator
// Immutable -> immutable indirect iterator
#ifdef BOOST_NO_STD_ITERATOR_TRAITS
class OuterTraits,
class InnerTraits
@ -549,13 +564,19 @@ struct reverse_iterators
// Projection Iterators Adaptor
template <class AdaptableUnaryFunction>
struct projection_iterator_policies :
public default_iterator_policies {
struct projection_iterator_policies : public default_iterator_policies
{
projection_iterator_policies() { }
projection_iterator_policies(const AdaptableUnaryFunction& f) : m_f(f) { }
template <class Reference, class Iterator>
Reference dereference (type<Reference>, Iterator const& it) const {
return AdaptableUnaryFunction()(*it);
Reference dereference (type<Reference>, Iterator const& iter) const {
return m_f(*iter);
}
AdaptableUnaryFunction m_f;
};
template <class AdaptableUnaryFunction, class Traits>
struct projection_iterator_traits {
typedef typename AdaptableUnaryFunction::result_type value_type;
@ -564,6 +585,7 @@ struct projection_iterator_traits {
typedef typename Traits::difference_type difference_type;
typedef typename Traits::iterator_category iterator_category;
};
template <class AdaptableUnaryFunction, class Traits>
struct const_projection_iterator_traits {
typedef typename AdaptableUnaryFunction::result_type value_type;
@ -572,6 +594,7 @@ struct const_projection_iterator_traits {
typedef typename Traits::difference_type difference_type;
typedef typename Traits::iterator_category iterator_category;
};
template <class AdaptableUnaryFunction, class Iterator,
#ifndef BOOST_NO_STD_ITERATOR_TRAITS
class Traits = std::iterator_traits<Iterator>
@ -586,6 +609,7 @@ struct projection_iterator {
projection_iterator_policies<AdaptableUnaryFunction>,
Projection_Traits> type;
};
template <class AdaptableUnaryFunction, class Iterator,
#ifndef BOOST_NO_STD_ITERATOR_TRAITS
class Traits = std::iterator_traits<Iterator>
@ -600,6 +624,7 @@ struct const_projection_iterator {
projection_iterator_policies<AdaptableUnaryFunction>,
Projection_Traits> type;
};
template <class AdaptableUnaryFunction, class Iterator, class ConstIterator,
#ifndef BOOST_NO_STD_ITERATOR_TRAITS
class Traits = std::iterator_traits<Iterator>,