subspacebasis.hh

// -*- tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
// vi: set et ts=4 sw=2 sts=2:
 
// SPDX-FileCopyrightText: Copyright © DUNE Project contributors, see file AUTHORS.md
// SPDX-License-Identifier: LicenseRef-GPL-2.0-only-with-DUNE-exception OR LGPL-3.0-or-later
 
#ifndef DUNE_FUNCTIONS_FUNCTIONSPACEBASES_SUBSPACEBASIS_HH
#define DUNE_FUNCTIONS_FUNCTIONSPACEBASES_SUBSPACEBASIS_HH
 
#include <dune/common/reservedvector.hh>
#include <dune/common/typeutilities.hh>
#include <dune/common/concept.hh>
 
#include <dune/functions/common/type_traits.hh>
#include <dune/functions/functionspacebases/subspacelocalview.hh>
#include <dune/functions/functionspacebases/concepts.hh>
 
 
 
namespace Dune {
namespace Functions {
 
 
 
namespace Impl {
 
  template<class... Inner, class... Outer>
  auto joinTreePaths(const TypeTree::HybridTreePath<Inner...>& inner, const TypeTree::HybridTreePath<Outer...> outer)
  {
    return TypeTree::HybridTreePath<Inner..., Outer...>(std::tuple_cat(inner._data, outer._data));
  }
 
  template<class InnerTP, class OuterTP>
  using JoinTreePath_t = std::decay_t<decltype(joinTreePaths(std::declval<InnerTP>(), std::declval<OuterTP>()))>;
 
}
 
 
 
template<class RB, class TP>
class SubspaceBasis
{
public:
 
  using RootBasis = RB;
 
  using RootLocalView = typename RootBasis::LocalView;
 
  using PrefixPath = TP;
 
  using GridView = typename RootBasis::GridView;
 
  using MultiIndex = typename RootBasis::MultiIndex;
 
  using size_type = std::size_t;
 
  using LocalView = SubspaceLocalView<RootLocalView, PrefixPath>;
 
  using SizePrefix = typename RootBasis::SizePrefix;
 
 
  SubspaceBasis(const RootBasis& rootBasis, const PrefixPath& prefixPath) :
    rootBasis_(&rootBasis),
    prefixPath_(prefixPath)
  {}
 
  template<class RootRootBasis, class InnerTP, class OuterTP>
  SubspaceBasis(const SubspaceBasis<RootRootBasis, InnerTP>& rootBasis, const OuterTP& prefixPath) :
    SubspaceBasis(rootBasis.rootBasis(), Impl::joinTreePaths(rootBasis.prefixPath(), prefixPath))
  {}
 
 
  const GridView& gridView() const
  {
    return rootBasis_->gridView();
  }
 
  size_type dimension() const
  {
    return rootBasis_->dimension();
  }
 
  size_type size() const
  {
    return rootBasis_->size();
  }
 
  size_type size(const SizePrefix& prefix) const
  {
    return rootBasis_->size(prefix);
  }
 
  LocalView localView() const
  {
    return LocalView(*this, prefixPath_);
  }
 
  const RootBasis& rootBasis() const
  {
    return *rootBasis_;
  }
 
  const PrefixPath& prefixPath() const
  {
    return prefixPath_;
  }
 
protected:
  const RootBasis* rootBasis_;
  PrefixPath prefixPath_;
};
 
 
// CTAD guide for a non-SubspaceBasis root basis
template<class RB, class TP>
SubspaceBasis(const RB&, const TP) -> SubspaceBasis<RB, TP>;
 
// CTAD guide for a SubspaceBasis root basis
template<class RootRootBasis, class InnerTP, class OuterTP>
SubspaceBasis(const SubspaceBasis<RootRootBasis, InnerTP>& rootBasis, const OuterTP& prefixPath)
  -> SubspaceBasis<std::decay_t<decltype(rootBasis.rootBasis())>, Impl::JoinTreePath_t<InnerTP, OuterTP>>;
 
 
 
template<class RootBasis, class... PrefixTreeIndices>
auto subspaceBasis(const RootBasis& rootBasis, const TypeTree::HybridTreePath<PrefixTreeIndices...>& prefixPath)
{
  return SubspaceBasis(rootBasis, prefixPath);
}
 
template<class RootBasis, class... PrefixTreeIndices>
auto subspaceBasis(const RootBasis& rootBasis, const PrefixTreeIndices&... prefixTreeIndices)
{
  return subspaceBasis(rootBasis, TypeTree::hybridTreePath(prefixTreeIndices...));
}
 
 
 
} // end namespace Functions
} // end namespace Dune
 
 
 
#endif // DUNE_FUNCTIONS_FUNCTIONSPACEBASES_DEFAULTGLOBALBASIS_HH