metaprogramming_util.h

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/*
 * Copyright (c) 2010-2015:  G-CSC, Goethe University Frankfurt
 * Author: Andreas Vogel
 * 
 * This file is part of UG4.
 * 
 * UG4 is free software: you can redistribute it and/or modify it under the
 * terms of the GNU Lesser General Public License version 3 (as published by the
 * Free Software Foundation) with the following additional attribution
 * requirements (according to LGPL/GPL v3 §7):
 * 
 * (1) The following notice must be displayed in the Appropriate Legal Notices
 * of covered and combined works: "Based on UG4 (www.ug4.org/license)".
 * 
 * (2) The following notice must be displayed at a prominent place in the
 * terminal output of covered works: "Based on UG4 (www.ug4.org/license)".
 * 
 * (3) The following bibliography is recommended for citation and must be
 * preserved in all covered files:
 * "Reiter, S., Vogel, A., Heppner, I., Rupp, M., and Wittum, G. A massively
 *   parallel geometric multigrid solver on hierarchically distributed grids.
 *   Computing and visualization in science 16, 4 (2013), 151-164"
 * "Vogel, A., Reiter, S., Rupp, M., Nägel, A., and Wittum, G. UG4 -- a novel
 *   flexible software system for simulating pde based models on high performance
 *   computers. Computing and visualization in science 16, 4 (2013), 165-179"
 * 
 * This program 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 Lesser General Public License for more details.
 */
 
#ifndef __H__COMMON__METAPROGRAMMING_UTIL__
#define __H__COMMON__METAPROGRAMMING_UTIL__
 
namespace ug {
 
 
template <int N>
struct Int2Type {
  enum{ value = N};
  typedef int value_type;
};
 
template <class T>
struct Pointer2Value{};
 
template <class T>
struct Pointer2Value<T*>{
  typedef T type;
};
 
// TypeList
 
// empty type
struct EmptyType {};
 
// TypeList
template
<
  typename T1=EmptyType,
  typename T2=EmptyType,
  typename T3=EmptyType,
  typename T4=EmptyType,
  typename T5=EmptyType,
  typename T6=EmptyType,
  typename T7=EmptyType,
  typename T8=EmptyType,
  typename T9=EmptyType,
  typename T10=EmptyType,
  typename T11=EmptyType,
  typename T12=EmptyType
> struct TypeList;
 
// implementation of TypeList
template
<
  typename T1,
  typename T2,
  typename T3,
  typename T4,
  typename T5,
  typename T6,
  typename T7,
  typename T8,
  typename T9,
  typename T10,
  typename T11,
  typename T12
>
struct TypeList
{
  typedef T1 head;
  typedef TypeList< T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12 > tail;
  enum{length = tail::length+1};
};
 
// empty typelist specialization
template<>
struct TypeList< EmptyType, EmptyType, EmptyType, EmptyType,
         EmptyType, EmptyType, EmptyType, EmptyType, EmptyType,
         EmptyType, EmptyType, EmptyType>
{
  enum{length = 0};
};
 
// TypeValueList
 
// TypeList
template <typename TTypeList> struct TypeValueList
{
  typedef typename TTypeList::head head;
  typedef typename TTypeList::tail tail;
 
  head hd;
  TypeValueList<tail> tl;
 
  explicit TypeValueList() {
    std::cerr << "incomplete TVL\n";
  }
 
  TypeValueList(head _hd,
          TypeValueList<tail> typValList) :
    hd(_hd), tl(typValList) {}
 
};
 
template <>
struct TypeValueList< TypeList<> > {};
 
 
// Factorial
 
template <size_t n>
struct Factorial
{
    enum{value = n*Factorial<n-1>::value};
};
 
template <>
struct Factorial<1>
{
    enum {value = 1};
};
 
// Pow
 
template <int n, size_t d>
struct Pow
{
    enum{value = n*Pow<n, d-1>::value};
};
 
template <int n>
struct Pow<n, 0>
{
    enum {value = 1};
};
 
// BinomialCoefficient
 
template <size_t n, int k>
struct BinomialCoefficient
{
    enum { value =  Factorial<n>::value/
            (Factorial<k>::value*Factorial<n-k>::value) };
};
 
// end rekursion
template <size_t n>
struct BinomialCoefficient<n,0>
{
    enum { value = 1};
};
// end rekursion
template <size_t n>
struct BinomialCoefficient<n,-1>
{
    enum { value = 0};
};
// end rekursion
template <size_t n>
struct BinomialCoefficient<n,-2>
{
    enum { value = 0};
};
// end rekursion
template <size_t n>
struct BinomialCoefficient<n,-3>
{
    enum { value = 0};
};
// end rekursion
template <size_t n>
struct BinomialCoefficient<n,-4>
{
    enum { value = 0};
};
 
// UniqueTypeID (sreiter)
class UniqueTypeIDProvider{
  public:
    static UniqueTypeIDProvider& inst(){
      static UniqueTypeIDProvider utid;
      return utid;
    }
 
    size_t new_id() {return ++m_id;}
 
  private:
    UniqueTypeIDProvider() : m_id(0)  {}
    size_t m_id;
};
 
template <class TType>
size_t GetUniqueTypeID()
{
  static size_t typeID = UniqueTypeIDProvider::inst().new_id();
  return typeID;
}
 
// end group ugbase_common_util
 
}
 
#endif /* __H__COMMON__METAPROGRAMMING_UTIL__ */