unique.h

/***************************************************************************
 * include/stxxl/bits/stream/unique.h
 *
 * Part of the STXXL. See http://stxxl.sourceforge.net
 *
 * Copyright (C) 2003-2005 Roman Dementiev <[email protected]>
 * Copyright (C) 2010 Andreas Beckmann <[email protected]>
 *
 * Distributed under the Boost Software License, Version 1.0.
 * (See accompanying file LICENSE_1_0.txt or copy at
 * http://www.boost.org/LICENSE_1_0.txt)
 **************************************************************************/

#ifndef STXXL_STREAM__UNIQUE_H
#define STXXL_STREAM__UNIQUE_H

#include <stxxl/bits/namespace.h>


__STXXL_BEGIN_NAMESPACE

namespace stream
{
 // UNIQUE //

 struct dummy_cmp_unique_ { };

 template <class Input, class BinaryPredicate = dummy_cmp_unique_>
 class unique
 {
 Input & input;
 BinaryPredicate binary_pred;
 typename Input::value_type current;

 public:
 typedef typename Input::value_type value_type;

 unique(Input & input_, BinaryPredicate binary_pred_) : input(input_), binary_pred(binary_pred_)
 {
 if (!input.empty())
 current = *input;
 }

 unique & operator ++ ()
 {
 value_type old_value = current;
 ++input;
 while (!input.empty() && (binary_pred(current = *input, old_value)))
 ++input;
 return *this;
 }

 const value_type & operator * () const
 {
 return current;
 }

 const value_type * operator -> () const
 {
 return &current;
 }

 bool empty() const
 {
 return input.empty();
 }
 };

 template <class Input>
 class unique<Input, dummy_cmp_unique_>
 {
 Input & input;
 typename Input::value_type current;

 public:
 typedef typename Input::value_type value_type;

 unique(Input & input_) : input(input_)
 {
 if (!input.empty())
 current = *input;
 }

 unique & operator ++ ()
 {
 value_type old_value = current;
 ++input;
 while (!input.empty() && ((current = *input) == old_value))
 ++input;
 return *this;
 }

 const value_type & operator * () const
 {
 return current;
 }

 const value_type * operator -> () const
 {
 return &current;
 }

 bool empty() const
 {
 return input.empty();
 }
 };

}

__STXXL_END_NAMESPACE

#endif // !STXXL_STREAM__UNIQUE_H
// vim: et:ts=4:sw=4