choose.h

/***************************************************************************
 * include/stxxl/bits/stream/choose.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__CHOOSE_H_
#define STXXL_STREAM__CHOOSE_H_

#include <stxxl/bits/namespace.h>


__STXXL_BEGIN_NAMESPACE

namespace stream
{
 // CHOOSE //

 template <class Input_, int Which>
 class choose
 { };

 template <class Input_>
 class choose<Input_, 1>
 {
 Input_ & in;

 typedef typename Input_::value_type tuple_type;

 public:
 typedef typename tuple_type::first_type value_type;

 choose(Input_ & in_) : in(in_)
 { }

 const value_type & operator * () const
 {
 return (*in).first;
 }

 const value_type * operator -> () const
 {
 return &(*in).first;
 }

 choose & operator ++ ()
 {
 ++in;
 return *this;
 }

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

 template <class Input_>
 class choose<Input_, 2>
 {
 Input_ & in;

 typedef typename Input_::value_type tuple_type;

 public:
 typedef typename tuple_type::second_type value_type;

 choose(Input_ & in_) : in(in_)
 { }

 const value_type & operator * () const
 {
 return (*in).second;
 }

 const value_type * operator -> () const
 {
 return &(*in).second;
 }

 choose & operator ++ ()
 {
 ++in;
 return *this;
 }

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

 template <class Input_>
 class choose<Input_, 3>
 {
 Input_ & in;

 typedef typename Input_::value_type tuple_type;

 public:
 typedef typename tuple_type::third_type value_type;

 choose(Input_ & in_) : in(in_)
 { }

 const value_type & operator * () const
 {
 return (*in).third;
 }

 const value_type * operator -> () const
 {
 return &(*in).third;
 }

 choose & operator ++ ()
 {
 ++in;
 return *this;
 }

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

 template <class Input_>
 class choose<Input_, 4>
 {
 Input_ & in;

 typedef typename Input_::value_type tuple_type;

 public:
 typedef typename tuple_type::fourth_type value_type;

 choose(Input_ & in_) : in(in_)
 { }

 const value_type & operator * () const
 {
 return (*in).fourth;
 }

 const value_type * operator -> () const
 {
 return &(*in).fourth;
 }

 choose & operator ++ ()
 {
 ++in;
 return *this;
 }

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

 template <class Input_>
 class choose<Input_, 5>
 {
 Input_ & in;

 typedef typename Input_::value_type tuple_type;

 public:
 typedef typename tuple_type::fifth_type value_type;

 choose(Input_ & in_) : in(in_)
 { }

 const value_type & operator * () const
 {
 return (*in).fifth;
 }

 const value_type * operator -> () const
 {
 return &(*in).fifth;
 }

 choose & operator ++ ()
 {
 ++in;
 return *this;
 }

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

 template <class Input_>
 class choose<Input_, 6>
 {
 Input_ & in;

 typedef typename Input_::value_type tuple_type;

 public:
 typedef typename tuple_type::sixth_type value_type;

 choose(Input_ & in_) : in(in_)
 { }

 const value_type & operator * () const
 {
 return (*in).sixth;
 }

 const value_type * operator -> () const
 {
 return &(*in).sixth;
 }

 choose & operator ++ ()
 {
 ++in;
 return *this;
 }

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


}

__STXXL_END_NAMESPACE


#include <stxxl/bits/stream/unique.h>


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