Exheredludis/paludis/util/indirect_iterator.hh
2011-04-08 12:09:54 +01:00

144 lines
3.9 KiB
C++

/* vim: set sw=4 sts=4 et foldmethod=syntax : */
/*
* Copyright (c) 2007, 2008, 2011 Ciaran McCreesh
*
* This file is part of the Paludis package manager. Paludis is free software;
* you can redistribute it and/or modify it under the terms of the GNU General
* Public License version 2, as published by the Free Software Foundation.
*
* Paludis is distributed in the hope that it will be useful, but WITHOUT ANY
* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 59 Temple
* Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef PALUDIS_GUARD_PALUDIS_UTIL_INDIRECT_ITERATOR_HH
#define PALUDIS_GUARD_PALUDIS_UTIL_INDIRECT_ITERATOR_HH 1
#include <paludis/util/indirect_iterator-fwd.hh>
#include <paludis/util/operators.hh>
#include <memory>
#include <functional>
#include <type_traits>
namespace paludis
{
template <typename T_>
struct IndirectIteratorValueType
{
typedef typename std::iterator_traits<T_>::value_type Type;
};
template <typename T_>
struct IndirectIteratorValueType<T_ *>
{
typedef T_ Type;
};
template <typename T_>
struct IndirectIteratorValueType<std::shared_ptr<T_> >
{
typedef T_ Type;
};
template <typename T_>
struct IndirectIteratorValueType<std::shared_ptr<const T_> >
{
typedef const T_ Type;
};
template <typename T_>
struct IndirectIteratorValueType<const T_>
{
typedef typename IndirectIteratorValueType<T_>::Type Type;
};
template <typename T_>
struct IndirectIteratorValueType<T_ &>
{
typedef typename IndirectIteratorValueType<T_>::Type Type;
};
/**
* An IndirectIterator turns an iterator over T_ * or std::shared_ptr<T_> into an iterator
* over T_.
*
* \ingroup g_iterator
* \see indirect_iterator
*/
template <typename Iter_, typename Value_>
class IndirectIterator :
public relational_operators::HasRelationalOperators
{
friend bool operator== <> (const IndirectIterator &, const IndirectIterator &);
friend bool operator< <> (const IndirectIterator &, const IndirectIterator &);
private:
Iter_ _iter;
public:
///\name Basic operations
///\{
IndirectIterator();
IndirectIterator(const IndirectIterator &);
IndirectIterator(const Iter_ &);
IndirectIterator & operator= (const IndirectIterator &);
///\}
///\name Standard library typedefs
///\{
typedef typename std::remove_reference<Value_>::type & value_type;
typedef typename std::remove_reference<Value_>::type & reference;
typedef typename std::remove_reference<Value_>::type * pointer;
typedef std::ptrdiff_t difference_type;
typedef std::forward_iterator_tag iterator_category;
///\}
///\name Additional typedefs
///\{
typedef Iter_ underlying_iterator_type;
///\}
///\name Increment
///\{
IndirectIterator & operator++ ();
IndirectIterator operator++ (int);
///\}
///\name Dereference
///\{
pointer operator-> () const;
reference operator* () const;
underlying_iterator_type underlying_iterator();
///\}
};
/**
* Construct an IndirectIterator from another iterator.
*
* \see IndirectIterator
* \ingroup g_iterator
*/
template <typename Iter_>
IndirectIterator<Iter_> indirect_iterator(const Iter_ & t);
}
#endif