sequencesort.hh

#ifndef __DUNE_ACFEM_MPL_SEQUENCESORT_HH__
#define __DUNE_ACFEM_MPL_SEQUENCESORT_HH__
 
#include "generators.hh"
#include "typetuplesort.hh"
 
namespace Dune::ACFem::MPL {
 
  namespace {
 
    template<std::size_t I0, std::size_t I1>
    struct IndexPair
    {
      static constexpr std::size_t i0 = I0;
      static constexpr std::size_t i1 = I1;
    };
 
    template<class Tuple>
    struct UnpackSortData;
 
    template<std::size_t... I, std::size_t... P>
    struct UnpackSortData<TypeTuple<IndexPair<I, P>...> >
    {
      using Result = IndexSequence<I...>;
      using Permutation = IndexSequence<P...>;
    };
 
  }
 
  template<class Seq, template<std::size_t, std::size_t> class DoSwap, class Permutation = MakeSequenceFor<Seq> >
  struct SortSequence;
 
  template<std::size_t... I,  std::size_t... P, template<std::size_t, std::size_t> class DoSwap>
  struct SortSequence<IndexSequence<I...>, DoSwap, IndexSequence<P...> >
  {
    template<class A, class B>
    using Swap = DoSwap<A::i0, B::i0>;
 
    using SortData = TypeTuple<IndexPair<I, P>...>;
    using SortInfo = MergeSort<SortData, Swap>;
    using Result = typename UnpackSortData<SortInfo>::Result;
    using Permutation = typename UnpackSortData<SortInfo>::Permutation;
  };
 
  template<class Seq, template<std::size_t, std::size_t> class DoSwap>
  struct IsSorted;
 
  template<std::size_t... I,  template<std::size_t, std::size_t> class DoSwap>
  struct IsSorted<IndexSequence<I...>, DoSwap>
  {
    template<class A, class B>
    using Swap = DoSwap<A::value, B::value>;
 
    static constexpr bool value = IsSortedV<TypeTuple<IndexConstant<I>...>, Swap>;
  };
 
} // Dune::ACFem::MPL
 
#endif // __DUNE_ACFEM_MPL_SEQUENCESORT_HH__