lemon/bits/enable_if.h
author Peter Kovacs <kpeter@inf.elte.hu>
Thu, 09 Oct 2008 13:27:35 +0200
changeset 314 2cc60866a0c9
parent 220 a5d8c039f218
child 463 88ed40ad0d4f
permissions -rw-r--r--
Doc reorganization + improvements

- Reorganize several tools (move them to other modules).
- Add new module for map concepts.
- Remove the doc of all tools in lemon/bits.
- Improvements in groups.dox.
- Fix some doxygen warnings.
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/* -*- mode: C++; indent-tabs-mode: nil; -*-
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 *
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 * This file is a part of LEMON, a generic C++ optimization library.
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 *
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 * Copyright (C) 2003-2008
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 * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
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 * (Egervary Research Group on Combinatorial Optimization, EGRES).
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 *
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 * Permission to use, modify and distribute this software is granted
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 * provided that this copyright notice appears in all copies. For
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 * precise terms see the accompanying LICENSE file.
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 *
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 * This software is provided "AS IS" with no warranty of any kind,
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 * express or implied, and with no claim as to its suitability for any
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 * purpose.
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 *
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 */
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// This file contains a modified version of the enable_if library from BOOST.
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// See the appropriate copyright notice below.
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// Boost enable_if library
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// Copyright 2003 (c) The Trustees of Indiana University.
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// Use, modification, and distribution is subject to the Boost Software
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// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
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// http://www.boost.org/LICENSE_1_0.txt)
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//    Authors: Jaakko Jarvi (jajarvi at osl.iu.edu)
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//             Jeremiah Willcock (jewillco at osl.iu.edu)
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//             Andrew Lumsdaine (lums at osl.iu.edu)
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#ifndef LEMON_BITS_ENABLE_IF_H
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#define LEMON_BITS_ENABLE_IF_H
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//\file
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//\brief Miscellaneous basic utilities
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namespace lemon
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{
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  // Basic type for defining "tags". A "YES" condition for \c enable_if.
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  // Basic type for defining "tags". A "YES" condition for \c enable_if.
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  //
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  //\sa False
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  struct True {
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    //\e
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    static const bool value = true;
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  };
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  // Basic type for defining "tags". A "NO" condition for \c enable_if.
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  // Basic type for defining "tags". A "NO" condition for \c enable_if.
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  //
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  //\sa True
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  struct False {
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    //\e
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    static const bool value = false;
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  };
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  template <typename T>
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  struct Wrap {
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    const T &value;
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    Wrap(const T &t) : value(t) {}
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  };
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  /**************** dummy class to avoid ambiguity ****************/
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  template<int T> struct dummy { dummy(int) {} };
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  /**************** enable_if from BOOST ****************/
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  template <typename Type, typename T = void>
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  struct exists {
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    typedef T type;
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  };
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  template <bool B, class T = void>
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  struct enable_if_c {
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    typedef T type;
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  };
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  template <class T>
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  struct enable_if_c<false, T> {};
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  template <class Cond, class T = void>
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  struct enable_if : public enable_if_c<Cond::value, T> {};
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  template <bool B, class T>
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  struct lazy_enable_if_c {
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    typedef typename T::type type;
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  };
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  template <class T>
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  struct lazy_enable_if_c<false, T> {};
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  template <class Cond, class T>
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  struct lazy_enable_if : public lazy_enable_if_c<Cond::value, T> {};
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  template <bool B, class T = void>
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  struct disable_if_c {
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    typedef T type;
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  };
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  template <class T>
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  struct disable_if_c<true, T> {};
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  template <class Cond, class T = void>
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  struct disable_if : public disable_if_c<Cond::value, T> {};
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  template <bool B, class T>
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  struct lazy_disable_if_c {
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    typedef typename T::type type;
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  };
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  template <class T>
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  struct lazy_disable_if_c<true, T> {};
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  template <class Cond, class T>
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  struct lazy_disable_if : public lazy_disable_if_c<Cond::value, T> {};
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} // namespace lemon
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#endif