mirror of
https://github.com/boostorg/iterator.git
synced 2025-07-04 16:26:30 +02:00
ea4c7c7dd9
preventing the proper functionality of the underlying iterator being carried forward into the iterator adaptor. Also added is_bidirectional enum to avoid EDG compiler error. [SVN r9123]
1050 lines
37 KiB
C++
1050 lines
37 KiB
C++
// (C) Copyright David Abrahams 2000. Permission to copy, use,
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// modify, sell and distribute this software is granted provided this
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// copyright notice appears in all copies. This software is provided
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// "as is" without express or implied warranty, and with no claim as
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// to its suitability for any purpose.
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//
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// (C) Copyright Jeremy Siek 2000. Permission to copy, use, modify,
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// sell and distribute this software is granted provided this
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// copyright notice appears in all copies. This software is provided
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// "as is" without express or implied warranty, and with no claim as
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// to its suitability for any purpose.
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//
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// Revision History:
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// 11 Feb 2001 Jeremy Siek
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// Removed workaround for older MIPSpro compiler. The workaround
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// was preventing the proper functionality of the underlying
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// iterator being carried forward into the iterator adaptor.
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// Also added is_bidirectional enum to avoid EDG compiler error.
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// 11 Feb 2001 David Abrahams
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// Borland fixes up the wazoo. It finally works!
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// 10 Feb 2001 David Abrahams
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// Removed traits argument from iterator_adaptor<> and switched to
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// explicit trait specification for maximum ease-of-use.
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// Added comments to detail::iterator_defaults<>
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// Began using detail::iterator_defaults<> unconditionally for code clarity
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// Changed uses of `Iterator' to `Base' where non-iterators can be used.
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//
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// 10 Feb 2001 David Abrahams
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// Rolled in supposed Borland fixes from John Maddock, but not seeing any
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// improvement yet
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// Changed argument order to indirect_ generator, for convenience in the
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// case of input iterators (where Reference must be a value type).
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// Removed derivation of filter_iterator_policies from
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// default_iterator_policies, since the iterator category is likely to be
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// reduced (we don't want to allow illegal operations like decrement).
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// Support for a simpler filter iterator interface.
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//
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// 09 Feb 2001 David Abrahams
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// Improved interface to indirect_ and reverse_ iterators
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// Rolled back Jeremy's new constructor for now; it was causing
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// problems with counting_iterator_test
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// Attempted fix for Borland
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//
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// 09 Feb 2001 Jeremy Siek
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// Added iterator constructor to allow const adaptor
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// from non-const adaptee.
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// Changed make_xxx to pass iterators by-value to
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// get arrays converted to pointers.
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// Removed InnerIterator template parameter from
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// indirect_iterator_generator.
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// Rearranged parameters for make_filter_iterator
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//
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// 07 Feb 2001 Jeremy Siek
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// Removed some const iterator adaptor generators.
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// Added make_xxx_iterator() helper functions for remaining
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// iterator adaptors.
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// Removed some traits template parameters where they
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// where no longer needed thanks to detail::iterator_traits.
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// Moved some of the compile-time logic into enums for
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// EDG compatibility.
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//
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// 07 Feb 2001 David Abrahams
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// Removed iterator_adaptor_pair_generator and
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// reverse_iterator_pair_generator (more such culling to come)
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// Improved comments
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// Changed all uses of std::iterator_traits as default arguments
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// to boost::detail::iterator_traits for improved utility in
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// non-generic contexts
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// Fixed naming convention of non-template parameter names
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//
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// 06 Feb 2001 David Abrahams
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// Produce operator-> proxy objects for InputIterators
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// Added static assertions to do some basic concept checks
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// Renamed single-type generators -> xxx_generator
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// Renamed const/nonconst iterator generators -> xxx_pair_generator
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// Added make_transform_iterator(iter, function)
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// The existence of boost::detail::iterator_traits allowed many
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// template arguments to be defaulted. Some arguments had to be
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// moved to accomplish it.
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//
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// 04 Feb 2001 MWERKS bug workaround, concept checking for proper
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// reference types (David Abrahams)
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#ifndef BOOST_ITERATOR_ADAPTOR_DWA053000_HPP_
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# define BOOST_ITERATOR_ADAPTOR_DWA053000_HPP_
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# include <boost/iterator.hpp>
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# include <boost/utility.hpp>
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# include <boost/compressed_pair.hpp>
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# include <boost/concept_check.hpp>
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# include <boost/type.hpp>
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# include <boost/static_assert.hpp>
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# include <boost/type_traits.hpp>
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# include <boost/detail/iterator.hpp>
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# include <boost/detail/select_type.hpp>
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// I was having some problems with VC6. I couldn't tell whether our hack for
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// stock GCC was causing problems so I needed an easy way to turn it on and
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// off. Now we can test the hack with various compilers and still have an
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// "out" if it doesn't work. -dwa 7/31/00
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# if __GNUC__ == 2 && __GNUC_MINOR__ <= 96 && !defined(__STL_USE_NAMESPACES)
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# define BOOST_RELOPS_AMBIGUITY_BUG 1
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# endif
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namespace boost {
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//============================================================================
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// Concept checking classes that express the requirements for iterator
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// policies and adapted types. These classes are mostly for
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// documentation purposes, and are not used in this header file. They
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// merely provide a more succinct statement of what is expected of the
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// iterator policies.
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template <class Policies, class Adapted, class Traits>
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struct TrivialIteratorPoliciesConcept
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{
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typedef typename Traits::reference Reference;
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void constraints() {
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function_requires< AssignableConcept<Policies> >();
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function_requires< DefaultConstructibleConcept<Policies> >();
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function_requires< AssignableConcept<Adapted> >();
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function_requires< DefaultConstructibleConcept<Adapted> >();
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const_constraints();
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}
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void const_constraints() const {
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Reference r = p.dereference(type<Reference>(), x);
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b = p.equal(x, x);
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ignore_unused_variable_warning(r);
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}
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Policies p;
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Adapted x;
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mutable bool b;
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};
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// Add InputIteratorPoliciesConcept?
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template <class Policies, class Adapted, class Traits>
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struct ForwardIteratorPoliciesConcept
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{
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typedef typename Traits::iterator_category iterator_category;
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void constraints() {
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function_requires<
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TrivialIteratorPoliciesConcept<Policies, Adapted, Traits>
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>();
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p.increment(x);
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std::forward_iterator_tag t = iterator_category();
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ignore_unused_variable_warning(t);
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}
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Policies p;
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Adapted x;
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iterator_category category;
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};
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template <class Policies, class Adapted, class Traits>
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struct BidirectionalIteratorPoliciesConcept
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{
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typedef typename Traits::iterator_category iterator_category;
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void constraints() {
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function_requires<
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ForwardIteratorPoliciesConcept<Policies, Adapted, Traits>
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>();
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p.decrement(x);
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std::bidirectional_iterator_tag t = iterator_category();
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ignore_unused_variable_warning(t);
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}
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Policies p;
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Adapted x;
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};
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template <class Policies, class Adapted, class Traits>
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struct RandomAccessIteratorPoliciesConcept
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{
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typedef typename Traits::difference_type DifferenceType;
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typedef typename Traits::iterator_category iterator_category;
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void constraints() {
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function_requires<
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BidirectionalIteratorPoliciesConcept<Policies, Adapted, Traits>
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>();
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p.advance(x, n);
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std::random_access_iterator_tag t = iterator_category();
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const_constraints();
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ignore_unused_variable_warning(t);
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}
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void const_constraints() const {
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n = p.distance(type<DifferenceType>(), x, x);
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b = p.less(x, x);
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}
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Policies p;
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Adapted x;
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mutable DifferenceType n;
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mutable bool b;
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};
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//============================================================================
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// Default policies for iterator adaptors. You can use this as a base
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// class if you want to customize particular policies.
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struct default_iterator_policies
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{
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// Some of these members were defined static, but Borland got confused
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// and thought they were non-const. Also, Sun C++ does not like static
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// function templates.
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template <class Base>
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void initialize(Base&)
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{ }
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template <class Reference, class Base>
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Reference dereference(type<Reference>, const Base& x) const
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{ return *x; }
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template <class Base>
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void increment(Base& x)
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{ ++x; }
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template <class Base>
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void decrement(Base& x)
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{ --x; }
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template <class Base, class DifferenceType>
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void advance(Base& x, DifferenceType n)
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{ x += n; }
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template <class Difference, class Iterator1, class Iterator2>
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Difference distance(type<Difference>, const Iterator1& x,
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const Iterator2& y) const
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{ return y - x; }
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template <class Iterator1, class Iterator2>
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bool equal(const Iterator1& x, const Iterator2& y) const
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{ return x == y; }
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template <class Iterator1, class Iterator2>
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bool less(const Iterator1& x, const Iterator2& y) const
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{ return x < y; }
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};
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// putting the comparisons in a base class avoids the g++
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// ambiguous overload bug due to the relops operators
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#ifdef BOOST_RELOPS_AMBIGUITY_BUG
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template <class Derived, class Base>
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struct iterator_comparisons : Base { };
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template <class D1, class D2, class Base1, class Base2>
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inline bool operator==(const iterator_comparisons<D1,Base1>& xb,
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const iterator_comparisons<D2,Base2>& yb)
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{
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const D1& x = static_cast<const D1&>(xb);
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const D2& y = static_cast<const D2&>(yb);
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return x.policies().equal(x.iter(), y.iter());
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}
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template <class D1, class D2, class Base1, class Base2>
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inline bool operator!=(const iterator_comparisons<D1,Base1>& xb,
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const iterator_comparisons<D2,Base2>& yb)
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{
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const D1& x = static_cast<const D1&>(xb);
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const D2& y = static_cast<const D2&>(yb);
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return !x.policies().equal(x.iter(), y.iter());
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}
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template <class D1, class D2, class Base1, class Base2>
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inline bool operator<(const iterator_comparisons<D1,Base1>& xb,
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const iterator_comparisons<D2,Base2>& yb)
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{
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const D1& x = static_cast<const D1&>(xb);
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const D2& y = static_cast<const D2&>(yb);
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return x.policies().less(x.iter(), y.iter());
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}
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template <class D1, class D2, class Base1, class Base2>
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inline bool operator>(const iterator_comparisons<D1,Base1>& xb,
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const iterator_comparisons<D2,Base2>& yb)
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{
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const D1& x = static_cast<const D1&>(xb);
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const D2& y = static_cast<const D2&>(yb);
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return x.policies().less(y.iter(), x.iter());
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}
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template <class D1, class D2, class Base1, class Base2>
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inline bool operator>=(const iterator_comparisons<D1,Base1>& xb,
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const iterator_comparisons<D2,Base2>& yb)
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{
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const D1& x = static_cast<const D1&>(xb);
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const D2& y = static_cast<const D2&>(yb);
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return !x.policies().less(x.iter(), y.iter());
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}
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template <class D1, class D2, class Base1, class Base2>
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inline bool operator<=(const iterator_comparisons<D1,Base1>& xb,
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const iterator_comparisons<D2,Base2>& yb)
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{
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const D1& x = static_cast<const D1&>(xb);
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const D2& y = static_cast<const D2&>(yb);
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return !x.policies().less(y.iter(), x.iter());
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}
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#endif
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namespace detail {
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// operator->() needs special support for input iterators to strictly meet the
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// standard's requirements. If *i is not a reference type, we must still
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// produce a (constant) lvalue to which a pointer can be formed. We do that by
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// returning an instantiation of this special proxy class template.
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template <class T>
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struct operator_arrow_proxy
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{
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operator_arrow_proxy(const T& x) : m_value(x) {}
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const T* operator->() const { return &m_value; }
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T m_value;
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};
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template <class Iter>
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inline operator_arrow_proxy<typename Iter::value_type>
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operator_arrow(const Iter& i, std::input_iterator_tag) {
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return operator_arrow_proxy<
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#ifndef BOOST_MSVC
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typename
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#endif
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Iter::value_type>(*i);
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}
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template <class Iter>
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inline typename Iter::pointer
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operator_arrow(const Iter& i, std::forward_iterator_tag) {
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return &(*i);
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}
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template <class Category, class Value, class Pointer>
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struct operator_arrow_result_generator
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{
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typedef operator_arrow_proxy<Value> proxy;
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enum { is_input_iter = boost::is_convertible<Category,std::input_iterator_tag>::value
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& !boost::is_convertible<Category,std::forward_iterator_tag>::value };
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typedef typename boost::detail::if_true<(is_input_iter)>::template
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then<
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proxy,
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// else
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Pointer
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>::type type;
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};
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# ifdef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
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// Select default pointer and reference types for adapted non-pointer
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// iterators based on the iterator and the value_type. Poor man's partial
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// specialization is in use here.
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template <bool is_pointer>
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struct iterator_defaults_select
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{
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template <class Iterator,class Value>
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struct traits
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{
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// The assumption is that iterator_traits can deduce these types
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// properly as long as the iterator is not a pointer.
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typedef typename boost::detail::iterator_traits<Iterator>::pointer pointer;
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typedef typename boost::detail::iterator_traits<Iterator>::reference reference;
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};
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};
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// Select default pointer and reference types for adapted pointer iterators
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// given a (possibly-const) value_type.
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template <>
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struct iterator_defaults_select<true>
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{
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template <class Iterator,class Value>
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struct traits
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{
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typedef Value* pointer;
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typedef Value& reference;
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};
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};
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// Consolidate selection of the default pointer and reference type
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template <class Iterator,class Value>
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struct iterator_defaults
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{
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enum { is_ptr = boost::is_pointer<Iterator>::value };
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typedef iterator_defaults_select<is_ptr>::template traits<Iterator,Value> traits;
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typedef typename traits::pointer pointer;
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typedef typename traits::reference reference;
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};
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# else
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template <class Iterator,class Value>
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struct iterator_defaults : iterator_traits<Iterator>
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{
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// Trying to factor the common is_same expression into an enum or a
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// static bool constant confused Borland.
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typedef typename if_true<(
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::boost::is_same<Value,typename iterator_traits<Iterator>::value_type>::value
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)>::template then<
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typename iterator_traits<Iterator>::pointer,
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Value*
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>::type pointer;
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typedef typename if_true<(
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::boost::is_same<Value,typename iterator_traits<Iterator>::value_type>::value
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)>::template then<
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typename iterator_traits<Iterator>::reference,
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Value&
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>::type reference;
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};
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# endif
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} // namespace detail
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// This macro definition is only temporary in this file
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# if !defined(BOOST_MSVC)
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# define BOOST_ARG_DEPENDENT_TYPENAME typename
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# else
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# define BOOST_ARG_DEPENDENT_TYPENAME
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# endif
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template <class T> struct undefined;
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//============================================================================
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//iterator_adaptor - Adapts a generic piece of data as an iterator. Adaptation
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// is especially easy if the data being adapted is itself an iterator
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//
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// Base - the base (usually iterator) type being wrapped.
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//
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// Policies - a set of policies determining how the resulting iterator
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// works.
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//
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// Value - if supplied, the value_type of the resulting iterator, unless
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// const. If const, a conforming compiler strips constness for the
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// value_type. If not supplied, iterator_traits<Base>::value_type is used
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//
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// Reference - the reference type of the resulting iterator, and in
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// particular, the result type of operator*(). If not supplied but
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// Value is supplied, Value& is used. Otherwise
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// iterator_traits<Base>::reference is used.
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//
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// Pointer - the pointer type of the resulting iterator, and in
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// particular, the result type of operator->(). If not
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// supplied but Value is supplied, Value* is used. Otherwise
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// iterator_traits<Base>::pointer is used.
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//
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// Category - the iterator_category of the resulting iterator. If not
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// supplied, iterator_traits<Base>::iterator_category is used.
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//
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// Distance - the difference_type of the resulting iterator. If not
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// supplied, iterator_traits<Base>::difference_type is used.
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template <class Base, class Policies,
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class Value = BOOST_ARG_DEPENDENT_TYPENAME boost::detail::iterator_traits<Base>::value_type,
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class Reference = BOOST_ARG_DEPENDENT_TYPENAME boost::detail::iterator_defaults<Base,Value>::reference,
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class Pointer = BOOST_ARG_DEPENDENT_TYPENAME boost::detail::iterator_defaults<Base,Value>::pointer,
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class Category = BOOST_ARG_DEPENDENT_TYPENAME boost::detail::iterator_traits<Base>::iterator_category,
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class Distance = BOOST_ARG_DEPENDENT_TYPENAME boost::detail::iterator_traits<Base>::difference_type
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>
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struct iterator_adaptor :
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#ifdef BOOST_RELOPS_AMBIGUITY_BUG
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iterator_comparisons<
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iterator_adaptor<Base,Policies,Value,Reference,Pointer,Category,Distance>,
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#endif
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boost::iterator<Category,Value,Distance,Pointer,Reference>
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#ifdef BOOST_RELOPS_AMBIGUITY_BUG
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>
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#endif
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{
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typedef iterator_adaptor<Base,Policies,Value,Reference,Pointer,Category,Distance> self;
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public:
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typedef Distance difference_type;
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typedef typename boost::remove_const<Value>::type value_type;
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typedef Pointer pointer;
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typedef Reference reference;
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typedef Category iterator_category;
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typedef Base base_type;
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enum { is_input_or_output_iter =
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boost::is_convertible<iterator_category*,std::input_iterator_tag*>::value
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|| boost::is_convertible<iterator_category*,std::output_iterator_tag*>::value };
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|
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// Iterators should satisfy one of the known categories
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BOOST_STATIC_ASSERT(is_input_or_output_iter);
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|
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// Iterators >= ForwardIterator must produce real references.
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enum { forward_iter_with_real_reference =
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(!boost::is_convertible<iterator_category*,std::forward_iterator_tag*>::value
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|| boost::is_same<reference,value_type&>::value
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|| boost::is_same<reference,const value_type&>::value) };
|
|
BOOST_STATIC_ASSERT(forward_iter_with_real_reference);
|
|
|
|
iterator_adaptor() { }
|
|
|
|
iterator_adaptor(const Base& it, const Policies& p = Policies())
|
|
: m_iter_p(it, p) {
|
|
policies().initialize(iter());
|
|
}
|
|
|
|
template <class Iter2, class Value2, class Pointer2, class Reference2>
|
|
iterator_adaptor (
|
|
const iterator_adaptor<Iter2,Policies,Value2,Reference2,Pointer2,Category,Distance>& src)
|
|
: m_iter_p(src.iter(), src.policies())
|
|
{
|
|
policies().initialize(iter());
|
|
}
|
|
|
|
#ifdef BOOST_MSVC
|
|
// This is required to prevent a bug in how VC++ generates
|
|
// the assignment operator for compressed_pair.
|
|
iterator_adaptor& operator= (const iterator_adaptor& x) {
|
|
m_iter_p = x.m_iter_p;
|
|
return *this;
|
|
}
|
|
#endif
|
|
reference operator*() const {
|
|
return policies().dereference(type<reference>(), iter());
|
|
}
|
|
|
|
#ifdef _MSC_VER
|
|
# pragma warning(push)
|
|
# pragma warning( disable : 4284 )
|
|
#endif
|
|
|
|
typename boost::detail::operator_arrow_result_generator<Category,value_type,Pointer>::type
|
|
operator->() const
|
|
{ return detail::operator_arrow(*this, Category()); }
|
|
|
|
#ifdef _MSC_VER
|
|
# pragma warning(pop)
|
|
#endif
|
|
|
|
value_type operator[](difference_type n) const
|
|
{ return *(*this + n); }
|
|
|
|
self& operator++() {
|
|
#ifdef __MWERKS__
|
|
// Odd bug, MWERKS couldn't deduce the type for the member template
|
|
// Workaround by explicitly specifying the type.
|
|
policies().increment<Base>(iter());
|
|
#else
|
|
policies().increment(iter());
|
|
#endif
|
|
return *this;
|
|
}
|
|
|
|
self operator++(int) { self tmp(*this); ++*this; return tmp; }
|
|
|
|
self& operator--() {
|
|
policies().decrement(iter());
|
|
return *this;
|
|
}
|
|
|
|
self operator--(int) { self tmp(*this); --*this; return tmp; }
|
|
|
|
self& operator+=(difference_type n) {
|
|
policies().advance(iter(), n);
|
|
return *this;
|
|
}
|
|
|
|
self& operator-=(difference_type n) {
|
|
policies().advance(iter(), -n);
|
|
return *this;
|
|
}
|
|
|
|
base_type base() const { return m_iter_p.first(); }
|
|
|
|
// Moved from global scope to avoid ambiguity with the operator-() which
|
|
// subtracts iterators from one another.
|
|
self operator-(Distance x)
|
|
{ self result(*this); return result -= x; }
|
|
private:
|
|
typedef Policies policies_type;
|
|
compressed_pair<Base,Policies> m_iter_p;
|
|
|
|
public: // implementation details (too many compilers have trouble when these are private).
|
|
Policies& policies() { return m_iter_p.second(); }
|
|
const Policies& policies() const { return m_iter_p.second(); }
|
|
|
|
Base& iter() { return m_iter_p.first(); }
|
|
const Base& iter() const { return m_iter_p.first(); }
|
|
};
|
|
|
|
template <class Base, class Policies, class Value, class Reference, class Pointer,
|
|
class Category, class Distance1, class Distance2>
|
|
iterator_adaptor<Base,Policies,Value,Reference,Pointer,Category,Distance1>
|
|
operator+(
|
|
iterator_adaptor<Base,Policies,Value,Reference,Pointer,Category,Distance1> p,
|
|
Distance2 x)
|
|
{
|
|
return p += x;
|
|
}
|
|
|
|
template <class Base, class Policies, class Value, class Reference, class Pointer,
|
|
class Category, class Distance1, class Distance2>
|
|
iterator_adaptor<Base,Policies,Value,Reference,Pointer,Category,Distance1>
|
|
operator+(
|
|
Distance2 x,
|
|
iterator_adaptor<Base,Policies,Value,Reference,Pointer,Category,Distance1> p)
|
|
{
|
|
return p += x;
|
|
}
|
|
|
|
template <class Iterator1, class Iterator2, class Policies, class Value1, class Value2,
|
|
class Reference1, class Reference2, class Pointer1, class Pointer2, class Category,
|
|
class Distance>
|
|
Distance operator-(
|
|
const iterator_adaptor<Iterator1,Policies,Value1,Reference1,Pointer1,Category,Distance>& x,
|
|
const iterator_adaptor<Iterator2,Policies,Value2,Reference2,Pointer2,Category,Distance>& y)
|
|
{
|
|
return x.policies().distance(type<Distance>(), y.iter(), x.iter());
|
|
}
|
|
|
|
#ifndef BOOST_RELOPS_AMBIGUITY_BUG
|
|
template <class Iterator1, class Iterator2, class Policies, class Value1, class Value2,
|
|
class Reference1, class Reference2, class Pointer1, class Pointer2,
|
|
class Category, class Distance>
|
|
inline bool
|
|
operator==(
|
|
const iterator_adaptor<Iterator1,Policies,Value1,Reference1,Pointer1,Category,Distance>& x,
|
|
const iterator_adaptor<Iterator2,Policies,Value2,Reference2,Pointer2,Category,Distance>& y)
|
|
{
|
|
return x.policies().equal(x.iter(), y.iter());
|
|
}
|
|
|
|
template <class Iterator1, class Iterator2, class Policies, class Value1, class Value2,
|
|
class Reference1, class Reference2, class Pointer1, class Pointer2,
|
|
class Category, class Distance>
|
|
inline bool
|
|
operator<(
|
|
const iterator_adaptor<Iterator1,Policies,Value1,Reference1,Pointer1,Category,Distance>& x,
|
|
const iterator_adaptor<Iterator2,Policies,Value2,Reference2,Pointer2,Category,Distance>& y)
|
|
{
|
|
return x.policies().less(x.iter(), y.iter());
|
|
}
|
|
|
|
template <class Iterator1, class Iterator2, class Policies, class Value1, class Value2,
|
|
class Reference1, class Reference2, class Pointer1, class Pointer2,
|
|
class Category, class Distance>
|
|
inline bool
|
|
operator>(
|
|
const iterator_adaptor<Iterator1,Policies,Value1,Reference1,Pointer1,Category,Distance>& x,
|
|
const iterator_adaptor<Iterator2,Policies,Value2,Reference2,Pointer2,Category,Distance>& y)
|
|
{
|
|
return x.policies().less(y.iter(), x.iter());
|
|
}
|
|
|
|
template <class Iterator1, class Iterator2, class Policies, class Value1, class Value2,
|
|
class Reference1, class Reference2, class Pointer1, class Pointer2,
|
|
class Category, class Distance>
|
|
inline bool
|
|
operator>=(
|
|
const iterator_adaptor<Iterator1,Policies,Value1,Reference1,Pointer1,Category,Distance>& x,
|
|
const iterator_adaptor<Iterator2,Policies,Value2,Reference2,Pointer2,Category,Distance>& y)
|
|
{
|
|
return !x.policies().less(x.iter(), y.iter());
|
|
}
|
|
|
|
template <class Iterator1, class Iterator2, class Policies, class Value1, class Value2,
|
|
class Reference1, class Reference2, class Pointer1, class Pointer2,
|
|
class Category, class Distance>
|
|
inline bool
|
|
operator<=(
|
|
const iterator_adaptor<Iterator1,Policies,Value1,Reference1,Pointer1,Category,Distance>& x,
|
|
const iterator_adaptor<Iterator2,Policies,Value2,Reference2,Pointer2,Category,Distance>& y)
|
|
{
|
|
return !x.policies().less(y.iter(), x.iter());
|
|
}
|
|
|
|
template <class Iterator1, class Iterator2, class Policies, class Value1, class Value2,
|
|
class Reference1, class Reference2, class Pointer1, class Pointer2,
|
|
class Category, class Distance>
|
|
inline bool
|
|
operator!=(
|
|
const iterator_adaptor<Iterator1,Policies,Value1,Reference1,Pointer1,Category,Distance>& x,
|
|
const iterator_adaptor<Iterator2,Policies,Value2,Reference2,Pointer2,Category,Distance>& y)
|
|
{
|
|
return !x.policies().equal(x.iter(), y.iter());
|
|
}
|
|
#endif
|
|
|
|
//=============================================================================
|
|
// 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
|
|
{
|
|
transform_iterator_policies() { }
|
|
transform_iterator_policies(const AdaptableUnaryFunction& f) : m_f(f) { }
|
|
|
|
template <class Reference, class Iterator>
|
|
Reference dereference(type<Reference>, const Iterator& iter) const
|
|
{ return m_f(*iter); }
|
|
|
|
AdaptableUnaryFunction m_f;
|
|
};
|
|
|
|
template <class AdaptableUnaryFunction, class Iterator>
|
|
class 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;
|
|
};
|
|
|
|
template <class AdaptableUnaryFunction, class Iterator>
|
|
inline 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);
|
|
}
|
|
|
|
//=============================================================================
|
|
// Indirect Iterators Adaptor
|
|
|
|
// 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
|
|
{
|
|
template <class Reference, class Iterator>
|
|
Reference dereference(type<Reference>, const Iterator& x) const
|
|
{ return **x; }
|
|
};
|
|
|
|
namespace detail {
|
|
# if !defined(BOOST_MSVC) // stragely instantiated even when unused! Maybe try a recursive template someday ;-)
|
|
template <class T>
|
|
struct value_type_of_value_type {
|
|
typedef typename boost::detail::iterator_traits<T>::value_type outer_value;
|
|
typedef typename boost::detail::iterator_traits<outer_value>::value_type type;
|
|
};
|
|
# endif
|
|
}
|
|
|
|
template <class OuterIterator, // Mutable or Immutable, does not matter
|
|
class Value
|
|
#if !defined(BOOST_MSVC)
|
|
= BOOST_ARG_DEPENDENT_TYPENAME detail::value_type_of_value_type<OuterIterator>::type
|
|
#endif
|
|
, class Reference = Value&
|
|
, class Pointer = Value*
|
|
>
|
|
struct indirect_iterator_generator
|
|
{
|
|
typedef iterator_adaptor<OuterIterator,
|
|
indirect_iterator_policies,Value,Reference,Pointer> type;
|
|
};
|
|
|
|
template <class OuterIterator, // Mutable or Immutable, does not matter
|
|
class Value
|
|
#if !defined(BOOST_MSVC)
|
|
= BOOST_ARG_DEPENDENT_TYPENAME detail::value_type_of_value_type<OuterIterator>::type
|
|
#endif
|
|
, class Pointer = Value*
|
|
, class Reference = Value&
|
|
, class ConstPointer = const Value*
|
|
, class ConstReference = const Value&
|
|
>
|
|
struct indirect_iterator_pair_generator
|
|
{
|
|
typedef typename indirect_iterator_generator<OuterIterator,
|
|
Value, Reference, Pointer>::type iterator;
|
|
typedef typename indirect_iterator_generator<OuterIterator,
|
|
Value, ConstReference, ConstPointer>::type const_iterator;
|
|
};
|
|
|
|
#ifndef BOOST_MSVC
|
|
template <class OuterIterator>
|
|
inline typename indirect_iterator_generator<OuterIterator>::type
|
|
make_indirect_iterator(OuterIterator base)
|
|
{
|
|
typedef typename indirect_iterator_generator
|
|
<OuterIterator>::type result_t;
|
|
return result_t(base);
|
|
}
|
|
#endif
|
|
|
|
//=============================================================================
|
|
// Reverse Iterators Adaptor
|
|
|
|
struct reverse_iterator_policies : public default_iterator_policies
|
|
{
|
|
template <class Reference, class BidirectionalIterator>
|
|
Reference dereference(type<Reference>, const BidirectionalIterator& x) const
|
|
{ return *boost::prior(x); }
|
|
|
|
template <class BidirectionalIterator>
|
|
void increment(BidirectionalIterator& x) const
|
|
{ --x; }
|
|
|
|
template <class BidirectionalIterator>
|
|
void decrement(BidirectionalIterator& x) const
|
|
{ ++x; }
|
|
|
|
template <class BidirectionalIterator, class DifferenceType>
|
|
void advance(BidirectionalIterator& x, DifferenceType n) const
|
|
{ x -= n; }
|
|
|
|
template <class Difference, class Iterator1, class Iterator2>
|
|
Difference distance(type<Difference>, const Iterator1& x,
|
|
const Iterator2& y) const
|
|
{ return x - y; }
|
|
|
|
template <class Iterator1, class Iterator2>
|
|
bool equal(const Iterator1& x, const Iterator2& y) const
|
|
{ return x == y; }
|
|
|
|
template <class Iterator1, class Iterator2>
|
|
bool less(const Iterator1& x, const Iterator2& y) const
|
|
{ return y < x; }
|
|
};
|
|
|
|
template <class BidirectionalIterator,
|
|
class Value = BOOST_ARG_DEPENDENT_TYPENAME boost::detail::iterator_traits<BidirectionalIterator>::value_type,
|
|
class Reference = BOOST_ARG_DEPENDENT_TYPENAME boost::detail::iterator_defaults<BidirectionalIterator,Value>::reference,
|
|
class Pointer = BOOST_ARG_DEPENDENT_TYPENAME boost::detail::iterator_defaults<BidirectionalIterator,Value>::pointer,
|
|
class Category = BOOST_ARG_DEPENDENT_TYPENAME boost::detail::iterator_traits<BidirectionalIterator>::iterator_category,
|
|
class Distance = BOOST_ARG_DEPENDENT_TYPENAME boost::detail::iterator_traits<BidirectionalIterator>::difference_type
|
|
>
|
|
struct reverse_iterator_generator
|
|
{
|
|
typedef iterator_adaptor<BidirectionalIterator,reverse_iterator_policies,
|
|
Value,Reference,Pointer,Category,Distance> type;
|
|
};
|
|
|
|
template <class BidirectionalIterator>
|
|
inline typename reverse_iterator_generator<BidirectionalIterator>::type
|
|
make_reverse_iterator(BidirectionalIterator base)
|
|
{
|
|
typedef typename reverse_iterator_generator<BidirectionalIterator>::type result_t;
|
|
return result_t(base);
|
|
}
|
|
|
|
//=============================================================================
|
|
// Projection Iterators Adaptor
|
|
|
|
template <class AdaptableUnaryFunction>
|
|
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& iter) const {
|
|
return m_f(*iter);
|
|
}
|
|
|
|
AdaptableUnaryFunction m_f;
|
|
};
|
|
|
|
template <class AdaptableUnaryFunction, class Iterator>
|
|
class projection_iterator_generator {
|
|
typedef typename AdaptableUnaryFunction::result_type value_type;
|
|
typedef projection_iterator_policies<AdaptableUnaryFunction> policies;
|
|
public:
|
|
typedef iterator_adaptor<Iterator,policies,value_type> type;
|
|
};
|
|
|
|
template <class AdaptableUnaryFunction, class Iterator>
|
|
class const_projection_iterator_generator {
|
|
typedef typename AdaptableUnaryFunction::result_type value_type;
|
|
typedef projection_iterator_policies<AdaptableUnaryFunction> policies;
|
|
public:
|
|
typedef iterator_adaptor<Iterator,policies,value_type,const value_type&,const value_type*> type;
|
|
};
|
|
|
|
template <class AdaptableUnaryFunction, class Iterator, class ConstIterator>
|
|
struct projection_iterator_pair_generator {
|
|
typedef typename projection_iterator_generator<AdaptableUnaryFunction, Iterator>::type iterator;
|
|
typedef typename const_projection_iterator_generator<AdaptableUnaryFunction, Iterator>::type const_iterator;
|
|
};
|
|
|
|
|
|
template <class AdaptableUnaryFunction, class Iterator>
|
|
inline typename projection_iterator_generator<AdaptableUnaryFunction, Iterator>::type
|
|
make_projection_iterator(
|
|
Iterator iter,
|
|
const AdaptableUnaryFunction& f = AdaptableUnaryFunction())
|
|
{
|
|
typedef typename projection_iterator_generator<AdaptableUnaryFunction, Iterator>::type result_t;
|
|
return result_t(iter, f);
|
|
}
|
|
|
|
template <class AdaptableUnaryFunction, class Iterator>
|
|
inline typename const_projection_iterator_generator<AdaptableUnaryFunction, Iterator>::type
|
|
make_const_projection_iterator(
|
|
Iterator iter,
|
|
const AdaptableUnaryFunction& f = AdaptableUnaryFunction())
|
|
{
|
|
typedef typename const_projection_iterator_generator<AdaptableUnaryFunction, Iterator>::type result_t;
|
|
return result_t(iter, f);
|
|
}
|
|
|
|
//=============================================================================
|
|
// Filter Iterator Adaptor
|
|
|
|
template <class Predicate, class Iterator>
|
|
class filter_iterator_policies
|
|
{
|
|
public:
|
|
filter_iterator_policies() { }
|
|
|
|
filter_iterator_policies(const Predicate& p, const Iterator& end)
|
|
: m_predicate(p), m_end(end) { }
|
|
|
|
void initialize(Iterator& x) {
|
|
satisfy_predicate(x);
|
|
}
|
|
|
|
// The Iter template argument is neccessary for compatibility with a MWCW
|
|
// bug workaround
|
|
template <class Iter>
|
|
void increment(Iter& x) {
|
|
++x;
|
|
satisfy_predicate(x);
|
|
}
|
|
|
|
template <class Reference, class Iter>
|
|
Reference dereference(type<Reference>, const Iter& x) const
|
|
{ return *x; }
|
|
|
|
template <class Iterator1, class Iterator2>
|
|
bool equal(const Iterator1& x, const Iterator2& y) const
|
|
{ return x == y; }
|
|
|
|
private:
|
|
void satisfy_predicate(Iterator& iter)
|
|
{
|
|
while (m_end != iter && !m_predicate(*iter))
|
|
++iter;
|
|
}
|
|
Predicate m_predicate;
|
|
Iterator m_end;
|
|
};
|
|
|
|
namespace detail {
|
|
// A type generator returning Base if T is derived from Base, and T otherwise.
|
|
template <class Base, class T>
|
|
struct reduce_to_base_class
|
|
{
|
|
typedef typename if_true<(
|
|
::boost::is_convertible<T*,Base*>::value
|
|
)>::template then<Base,T>::type type;
|
|
};
|
|
|
|
// "Steps down" the category of iterators below bidirectional so the category
|
|
// can be used with filter iterators.
|
|
template <class Iterator>
|
|
struct non_bidirectional_category
|
|
{
|
|
# if !defined(__MWERKS__) || __MWERKS__ > 0x4000
|
|
typedef typename reduce_to_base_class<
|
|
std::forward_iterator_tag,
|
|
typename iterator_traits<Iterator>::iterator_category
|
|
>::type type;
|
|
private:
|
|
// For some reason, putting this assertion in filter_iterator_generator fails inexplicably under MSVC
|
|
enum { is_bidirectional = (!boost::is_convertible<type*, std::bidirectional_iterator_tag*>::value) };
|
|
BOOST_STATIC_ASSERT(is_bidirectional);
|
|
# else
|
|
// is_convertible doesn't work with MWERKS
|
|
typedef typename iterator_traits<Iterator>::iterator_category input_category;
|
|
typedef typename if_true<(
|
|
boost::is_same<input_category,std::random_access_iterator_tag>::value
|
|
|| boost::is_same<input_category,std::bidirectional_iterator_tag>::value
|
|
)>::template then<
|
|
std::forward_iterator_tag,
|
|
input_category
|
|
>::type type;
|
|
# endif
|
|
};
|
|
}
|
|
|
|
template <class Predicate, class Iterator,
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class Value = BOOST_ARG_DEPENDENT_TYPENAME boost::detail::iterator_traits<Iterator>::value_type,
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class Reference = BOOST_ARG_DEPENDENT_TYPENAME boost::detail::iterator_defaults<Iterator,Value>::reference,
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class Pointer = BOOST_ARG_DEPENDENT_TYPENAME boost::detail::iterator_defaults<Iterator,Value>::pointer,
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class Category = BOOST_ARG_DEPENDENT_TYPENAME boost::detail::non_bidirectional_category<Iterator>::type,
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class Distance = BOOST_ARG_DEPENDENT_TYPENAME boost::detail::iterator_traits<Iterator>::difference_type
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>
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class filter_iterator_generator {
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#ifndef __BORLANDC__
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enum {
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#else
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static const bool
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#endif
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is_bidirectional
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= boost::is_convertible<Category*, std::bidirectional_iterator_tag*>::value
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#ifndef __BORLANDC__
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}
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#endif
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;
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#ifndef BOOST_MSVC // I don't have any idea why this occurs, but it doesn't seem to hurt too badly.
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BOOST_STATIC_ASSERT(!is_bidirectional);
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#endif
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public:
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typedef filter_iterator_policies<Predicate,Iterator> policies_type;
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typedef iterator_adaptor<Iterator,policies_type,
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Value,Reference,Pointer,Category,Distance> type;
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};
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// This keeps MSVC happy; it doesn't like to deduce default template arguments
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// for template function return types
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namespace detail {
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template <class Predicate, class Iterator>
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struct filter_generator {
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typedef typename boost::filter_iterator_generator<Predicate,Iterator>::type type;
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};
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}
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template <class Predicate, class Iterator>
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inline typename detail::filter_generator<Predicate, Iterator>::type
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make_filter_iterator(Iterator first, Iterator last, const Predicate& p = Predicate())
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{
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typedef filter_iterator_generator<Predicate, Iterator> Gen;
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typedef filter_iterator_policies<Predicate,Iterator> policies_t;
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typedef typename Gen::type result_t;
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return result_t(first, policies_t(p, last));
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}
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} // namespace boost
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# undef BOOST_ARG_DEPENDENT_TYPENAME
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#endif
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