Reduce errors and compiletime in tree traversal

cmake/modules/AmdisCXXFeatures.cmake

-#include(CheckIncludeFileCXX)
 include(CheckCXXSourceCompiles)
-#include(CheckCXXSymbolExists)
 
 # fold expressions (a + ...)
 check_cxx_source_compiles("
@@ -30,4 +28,16 @@ check_cxx_source_compiles("
     return f<1>();
   }
 "  AMDIS_HAS_CXX_CONSTEXPR_IF
+)
+
+check_cxx_source_compiles("
+  #include <iostream>
+  #include <tuple>
+  int main()
+  {
+    auto tup = std::make_tuple(0, 'a', 3.14);
+    for... (auto elem : tup)
+      std::cout << elem << std::endl;
+  }
+"  AMDIS_HAS_EXPANSION_STATEMENTS
 )
\ No newline at end of file

config.h.cmake

@@ -49,6 +49,7 @@
 /* some detected compiler features may be used in AMDiS */
 #cmakedefine AMDIS_HAS_CXX_FOLD_EXPRESSIONS 1
 #cmakedefine AMDIS_HAS_CXX_CONSTEXPR_IF 1
+#cmakedefine AMDIS_HAS_EXPANSION_STATEMENTS 1
 
 /* end amdis
    Everything below here will be overwritten

examples/CMakeLists.txt

@@ -24,4 +24,4 @@ add_dependencies(examples
   stokes1.2d
   stokes3.2d
   navier_stokes.2d
-  convection_diffusion.2d)
\ No newline at end of file
+  convection_diffusion.2d)

src/amdis/BoundaryManager.hpp

@@ -146,9 +146,10 @@ namespace AMDiS
           if (!segment.boundary())
             continue;
 
-          auto index = segment.boundarySegmentIndex();
-          Dune::Hybrid::ifElse(Dune::Std::is_detected<HasBoundaryId, Segment>{},
-            [&](auto id) { boundaryIds_[index] = id(segment).boundaryId(); });
+          Dune::Hybrid::ifElse(Dune::Std::is_detected<HasBoundaryId, Segment>{}, [&](auto id) {
+            auto index = segment.boundarySegmentIndex();
+            boundaryIds_[index] = id(segment).boundaryId();
+          });
         }
       }
     }

src/amdis/DataTransfer.inc.hpp

@@ -22,8 +22,8 @@
 
 #include <amdis/Output.hpp>
 #include <amdis/common/ConcurrentCache.hpp>
+#include <amdis/typetree/Traversal.hpp>
 #include <amdis/typetree/TreeContainer.hpp>
-#include <amdis/typetree/Visitor.hpp>
 
 namespace AMDiS
 {
@@ -135,7 +135,7 @@ namespace AMDiS
     auto lv = basis_->localView();
     auto const& idSet = gv.grid().localIdSet();
 
-    forEachLeafNode_(lv.tree(), [&](auto const& node, auto const& tp) {
+    for_each_leaf_node(lv.tree(), [&](auto const& node, auto const& tp) {
       nodeDataTransfer_[tp].preAdaptInit(lv, coeff, node);
     });
 
@@ -148,7 +148,7 @@ namespace AMDiS
 
       lv.bind(e);
       auto& treeContainer = it.first->second;
-      forEachLeafNode_(lv.tree(), [&](auto const& node, auto const& tp) {
+      for_each_leaf_node(lv.tree(), [&](auto const& node, auto const& tp) {
         nodeDataTransfer_[tp].cacheLocal(treeContainer[tp]);
       });
     }
@@ -201,7 +201,7 @@ namespace AMDiS
                 };
 
                 restrictLocalCompleted = true;
-                forEachLeafNode_(lv.tree(), [&](auto const& node, auto const& tp) {
+                for_each_leaf_node(lv.tree(), [&](auto const& node, auto const& tp) {
                   restrictLocalCompleted &=
                     nodeDataTransfer_[tp].restrictLocal(father, treeContainer[tp], xInChildCached,
                                                         childContainer[tp], init);
@@ -224,7 +224,7 @@ namespace AMDiS
     auto gv = basis_->gridView();
     auto lv = basis_->localView();
     auto const& idSet = gv.grid().localIdSet();
-    forEachLeafNode_(lv.tree(), [&](auto const& node, auto const& tp) {
+    for_each_leaf_node(lv.tree(), [&](auto const& node, auto const& tp) {
       nodeDataTransfer_[tp].postAdaptInit(lv, coeff, node);
     });
 
@@ -243,7 +243,7 @@ namespace AMDiS
       if (it != persistentContainer_.end()) {
         lv.bind(e);
         auto const& treeContainer = it->second;
-        forEachLeafNode_(lv.tree(), [&](auto const& node, auto const& tp) {
+        for_each_leaf_node(lv.tree(), [&](auto const& node, auto const& tp) {
           nodeDataTransfer_[tp].copyLocal(treeContainer[tp]);
         });
         finished_[index] = true;
@@ -275,7 +275,7 @@ namespace AMDiS
               return fatherGeo.local(childGeo.global(x));
             };
 
-            forEachLeafNode_(lv.tree(), [&](auto const& node, auto const& tp) {
+            for_each_leaf_node(lv.tree(), [&](auto const& node, auto const& tp) {
               nodeDataTransfer_[tp].prolongLocal(father, treeContainer[tp], xInFather, init);
             });
 

src/amdis/DirichletBC.hpp

@@ -11,8 +11,8 @@
 #include <amdis/BoundaryCondition.hpp>
 #include <amdis/common/Concepts.hpp>
 #include <amdis/typetree/RangeType.hpp>
+#include <amdis/typetree/Traversal.hpp>
 #include <amdis/typetree/TreeData.hpp>
-#include <amdis/typetree/Visitor.hpp>
 
 namespace AMDiS
 {

src/amdis/PeriodicBC.inc.hpp

@@ -196,7 +196,7 @@ std::vector<D> PeriodicBC<D,MI>::
 coords(Node const& tree, std::vector<std::size_t> const& localIndices) const
 {
   std::vector<D> dofCoords(localIndices.size());
-  AMDiS::forEachLeafNode_(tree, [&](auto const& node, auto const& tp)
+  for_each_leaf_node(tree, [&](auto const& node, auto const& tp)
   {
     std::size_t size = node.finiteElement().size();
     auto geometry = node.element().geometry();

src/amdis/ProblemStat.inc.hpp

@@ -177,7 +177,7 @@ void ProblemStat<Traits>::createMatricesAndVectors()
   rhs_ = std::make_shared<SystemVector>(*globalBasis_, NO_OPERATION);
 
   auto localView = globalBasis_->localView();
-  AMDiS::forEachNode_(localView.tree(), [&,this](auto const& node, auto treePath)
+  for_each_node(localView.tree(), [&,this](auto const& node, auto treePath)
   {
     std::string i = to_string(treePath);
     estimates_[i].resize(globalBasis_->gridView().indexSet().size(0));
@@ -205,7 +205,7 @@ void ProblemStat<Traits>::createMarker()
 {
   marker_.clear();
   auto localView = globalBasis_->localView();
-  AMDiS::forEachNode_(localView.tree(), [&,this](auto const& node, auto treePath)
+  for_each_node(localView.tree(), [&,this](auto const& node, auto treePath)
   {
     std::string componentName = name_ + "->marker[" + to_string(treePath) + "]";
 
@@ -232,7 +232,7 @@ void ProblemStat<Traits>::createFileWriter()
 {
   filewriter_.clear();
   auto localView = globalBasis_->localView();
-  forEachNode_(localView.tree(), [&,this](auto const& node, auto treePath)
+  for_each_node(localView.tree(), [&,this](auto const& node, auto treePath)
   {
     std::string componentName = name_ + "->output[" + to_string(treePath) + "]";
 
@@ -428,9 +428,9 @@ buildAfterAdapt(AdaptInfo& /*adaptInfo*/, Flag /*flag*/, bool asmMatrix, bool as
   rhs_->init(asmVector);
 
   auto localView = globalBasis_->localView();
-  forEachNode_(localView.tree(), [&,this](auto const& rowNode, auto rowTp) {
+  for_each_node(localView.tree(), [&,this](auto const& rowNode, auto rowTp) {
     auto rowBasis = Dune::Functions::subspaceBasis(*globalBasis_, rowTp);
-    forEachNode_(localView.tree(), [&,this](auto const& colNode, auto colTp) {
+    for_each_node(localView.tree(), [&,this](auto const& colNode, auto colTp) {
       auto colBasis = Dune::Functions::subspaceBasis(*globalBasis_, colTp);
       for (auto bc : dirichletBCs_[rowNode][colNode])
         bc->init(rowBasis, colBasis);
@@ -456,8 +456,8 @@ buildAfterAdapt(AdaptInfo& /*adaptInfo*/, Flag /*flag*/, bool asmMatrix, bool as
   systemMatrix_->finish(asmMatrix);
   rhs_->finish(asmVector);
 
-  forEachNode_(localView.tree(), [&,this](auto const& rowNode, auto) {
-    forEachNode_(localView.tree(), [&,this](auto const& colNode, auto) {
+  for_each_node(localView.tree(), [&,this](auto const& rowNode, auto) {
+    for_each_node(localView.tree(), [&,this](auto const& colNode, auto) {
       // finish boundary condition
       for (auto bc : dirichletBCs_[rowNode][colNode])
         bc->fillBoundaryCondition(*systemMatrix_, *solution_, *rhs_, rowNode, colNode);

src/amdis/common/ForEach.hpp

@@ -2,7 +2,6 @@
 
 #include <initializer_list>
 
-#include <amdis/common/Apply.hpp>
 #include <amdis/common/Index.hpp>
 #include <amdis/common/Range.hpp>
 
@@ -16,34 +15,52 @@ namespace AMDiS
       void ignored_evaluation(std::initializer_list<T>&&) { /* do nothing */ }
     }
 
+    template <std::size_t... I, class Tuple, class Functor>
+    constexpr void for_each(std::index_sequence<I...>, Tuple&& tuple, Functor&& f)
+    {
+      using std::get;
+#if AMDIS_HAS_EXPANSION_STATEMENTS
+      for... (auto&& t : tuple) { f(FWD(t)); }
+#elif AMDIS_HAS_CXX_FOLD_EXPRESSIONS
+      (f(get<I>(tuple)),...);
+#else
+      Impl_::ignored_evaluation<int>({0, (f(get<I>(tuple)), 0)...});
+#endif
+    }
+
     template <class Tuple, class Functor>
     constexpr void for_each(Tuple&& tuple, Functor&& f)
     {
-  #if AMDIS_HAS_CXX_FOLD_EXPRESSIONS
-      Tools::apply([f=std::move(f)](auto&&... t) { (f(FWD(t)),...); }, tuple);
-  #else
-      Tools::apply([f=std::move(f)](auto&&... t) {
-        Impl_::ignored_evaluation<int>({0, (f(FWD(t)), 0)...});
-      }, tuple);
-  #endif
+      Tools::for_each(std::make_index_sequence<Size_v<std::remove_reference_t<Tuple>>>{}, FWD(tuple), FWD(f));
+    }
+
+
+    template <std::size_t I0 = 0, std::size_t... I, class Functor>
+    constexpr void for_range(std::index_sequence<I...>, Functor&& f)
+    {
+#if AMDIS_HAS_CXX_FOLD_EXPRESSIONS
+      (f(index_t<I0+I>{}),...);
+#else
+      Impl_::ignored_evaluation<int>({0, (f(index_t<I0+I>{}), 0)...});
+#endif
     }
 
     template <std::size_t I0, std::size_t I1, class Functor>
     constexpr void for_range(index_t<I0> i0, index_t<I1> i1, Functor&& f)
     {
-      Tools::for_each(range_t<I0,I1>{}, FWD(f));
+      Tools::for_range<I0>(std::make_index_sequence<std::size_t(I1-I0)>{}, FWD(f));
     }
 
     template <std::size_t N, class Functor>
     constexpr void for_range(index_t<N>, Functor&& f)
     {
-      Tools::for_each(range_t<0,N>{}, FWD(f));
+      Tools::for_range(std::make_index_sequence<N>{}, FWD(f));
     }
 
     template <std::size_t I0, std::size_t I1, class Functor>
     constexpr void for_range(Functor&& f)
     {
-      Tools::for_each(range_t<I0,I1>{}, FWD(f));
+      Tools::for_range<I0>(std::make_index_sequence<std::size_t(I1-I0)>{}, FWD(f));
     }
 
   } // end namespace Tools

src/amdis/common/TypeTraits.hpp

@@ -65,6 +65,12 @@ namespace AMDiS
   template <class T>
   using owner = T;
 
+  /// A functor with no operation
+  struct NoOp
+  {
+    template <class... T>
+    constexpr void operator()(T&&...) const { /* no nothing */ }
+  };
 
   /// Create a unique_ptr by copy/move construction
   template <class Obj>

src/amdis/gridfunctions/DiscreteFunction.inc.hpp

@@ -147,7 +147,7 @@ LocalFunction::operator()(Domain const& x) const
 
   auto&& coefficients = *globalFunction_.dofVector_;
   auto&& nodeToRangeEntry = globalFunction_.nodeToRangeEntry_;
-  forEachLeafNode_(*subTree_, [&,this](auto const& node, auto const& tp)
+  for_each_leaf_node(*subTree_, [&,this](auto const& node, auto const& tp)
   {
     auto&& fe = node.finiteElement();
     auto&& localBasis = fe.localBasis();
@@ -193,7 +193,7 @@ GradientLocalFunction::operator()(Domain const& x) const
 
   auto&& coefficients = *globalFunction_.dofVector_;
   auto&& nodeToRangeEntry = globalFunction_.nodeToRangeEntry_;
-  forEachLeafNode_(*subTree_, [&,this](auto const& node, auto const& tp)
+  for_each_leaf_node(*subTree_, [&,this](auto const& node, auto const& tp)
   {
     // TODO: may DOFVectorView::Range to FieldVector type if necessary
     using LocalDerivativeTraits

src/amdis/linearalgebra/DOFMatrixBase.inc.hpp

@@ -2,7 +2,7 @@
 
 #include <amdis/Assembler.hpp>
 #include <amdis/LocalOperator.hpp>
-#include <amdis/typetree/Visitor.hpp>
+#include <amdis/typetree/Traversal.hpp>
 #include <amdis/utility/AssembleOperators.hpp>
 
 namespace AMDiS {
@@ -75,8 +75,8 @@ assemble(RowLocalView const& rowLocalView, ColLocalView const& colLocalView)
   auto const& element = rowLocalView.element();
   auto geometry = element.geometry();
 
-  forEachNode_(rowLocalView.tree(), [&](auto const& rowNode, auto) {
-    forEachNode_(colLocalView.tree(), [&](auto const& colNode, auto) {
+  for_each_node(rowLocalView.tree(), [&](auto const& rowNode, auto) {
+    for_each_node(colLocalView.tree(), [&](auto const& colNode, auto) {
       auto& matOp = operators_[rowNode][colNode];
       if (matOp) {
         matOp.bind(element, geometry);

src/amdis/linearalgebra/DOFVectorBase.inc.hpp

@@ -2,7 +2,7 @@
 
 #include <amdis/Assembler.hpp>
 #include <amdis/LocalOperator.hpp>
-#include <amdis/typetree/Visitor.hpp>
+#include <amdis/typetree/Traversal.hpp>
 #include <amdis/utility/AssembleOperators.hpp>
 
 namespace AMDiS {
@@ -66,7 +66,7 @@ assemble(LocalView const& localView)
   auto const& element = localView.element();
   auto geometry = element.geometry();
 
-  forEachNode_(localView.tree(), [&](auto const& node, auto) {
+  for_each_node(localView.tree(), [&](auto const& node, auto) {
     auto& rhsOp = operators_[node];
     if (rhsOp) {
       rhsOp.bind(element, geometry);

src/amdis/typetree/CMakeLists.txt

@@ -7,5 +7,4 @@ install(FILES
     TreeContainer.hpp
     TreeData.hpp
     TreePath.hpp
-    Visitor.hpp
 DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/amdis/typetree)

src/amdis/typetree/TreeData.hpp

@@ -6,7 +6,7 @@
 #include <vector>
 
 #include <dune/typetree/typetree.hh>
-#include <amdis/typetree/Visitor.hpp>
+#include <amdis/typetree/Traversal.hpp>
 
 namespace AMDiS
 {
@@ -195,10 +195,10 @@ namespace AMDiS
     }
 
     template <class Func>
-    void applyImpl(Func&& func, std::true_type) { forEachLeafNode_(basis_->localView().tree(), func); }
+    void applyImpl(Func&& func, std::true_type) { for_each_leaf_node(basis_->localView().tree(), func); }
 
     template <class Func>
-    void applyImpl(Func&& func, std::false_type) { forEachNode_(basis_->localView().tree(), func); }
+    void applyImpl(Func&& func, std::false_type) { for_each_node(basis_->localView().tree(), func); }
 
   protected:
     Basis const* basis_ = nullptr;
@@ -238,7 +238,7 @@ namespace AMDiS
     void init(RowBasis const& rowBasis, ColBasis const& colBasis)
     {
       Super::init(rowBasis);
-      forEachNode_(rowBasis.localView().tree(), [&](auto const& node, auto&&)
+      for_each_node(rowBasis.localView().tree(), [&](auto const& node, auto&&)
       {
         (*this)[node].init(colBasis);
       });

src/amdis/typetree/Visitor.hpp

-#pragma once
-
-#include <dune/typetree/visitor.hh>
-#include <amdis/typetree/Traversal.hpp>
-
-namespace AMDiS
-{
-  // from dune-typetree merge-request !2
-  namespace Impl
-  {
-    template <class PreFunc, class LeafFunc, class PostFunc>
-    class CallbackVisitor
-        : public Dune::TypeTree::TreeVisitor
-    {
-    public:
-      CallbackVisitor(PreFunc& preFunc, LeafFunc& leafFunc, PostFunc& postFunc)
-        : preFunc_(preFunc)
-        , leafFunc_(leafFunc)
-        , postFunc_(postFunc)
-      {}
-
-      template <typename Node, typename TreePath>
-      void pre(Node&& node, TreePath treePath)
-      {
-        preFunc_(node, treePath);
-      }
-
-      template <typename Node, typename TreePath>
-      void leaf(Node&& node, TreePath treePath)
-      {
-        leafFunc_(node, treePath);
-      }
-
-      template <typename Node, typename TreePath>
-      void post(Node&& node, TreePath treePath)
-      {
-        postFunc_(node, treePath);
-      }
-
-    private:
-      PreFunc& preFunc_;
-      LeafFunc& leafFunc_;
-      PostFunc& postFunc_;
-    };
-
-    template <class PreFunc, class LeafFunc, class PostFunc>
-    auto callbackVisitor(PreFunc& preFunc, LeafFunc& leafFunc, PostFunc& postFunc)
-    {
-      return CallbackVisitor<PreFunc, LeafFunc, PostFunc>(preFunc, leafFunc, postFunc);
-    }
-
-  } // namespace Impl
-
-
-  /**
-    * \brief Traverse tree and visit each node
-    *
-    * All passed callback functions are called with the
-    * node and corresponding treepath as arguments.
-    *
-    * \param tree The tree to traverse
-    * \param preFunc This function is called for each inner node before visiting its children
-    * \param leafFunc This function is called for each leaf node
-    * \param postFunc This function is called for each inner node after visiting its children
-    */
-  template <class Tree, class PreFunc, class LeafFunc, class PostFunc>
-  void forEachNode_(Tree&& tree, PreFunc&& preFunc, LeafFunc&& leafFunc, PostFunc&& postFunc)
-  {
-    traverseTree(tree, Impl::callbackVisitor(preFunc, leafFunc, postFunc));
-  }
-
-  /**
-    * \brief Traverse tree and visit each node
-    *
-    * All passed callback functions are called with the
-    * node and corresponding treepath as arguments.
-    *
-    * \param tree The tree to traverse
-    * \param innerFunc This function is called for each inner node before visiting its children
-    * \param leafFunc This function is called for each leaf node
-    */
-  template <class Tree, class InnerFunc, class LeafFunc>
-  void forEachNode_(Tree&& tree, InnerFunc&& innerFunc, LeafFunc&& leafFunc)
-  {
-    auto nop = [](auto&&... args) {};
-    forEachNode_(tree, innerFunc, leafFunc, nop);
-  }
-
-  /**
-    * \brief Traverse tree and visit each node
-    *
-    * The passed callback function is called with the
-    * node and corresponding treepath as arguments.
-    *
-    * \param tree The tree to traverse
-    * \param nodeFunc This function is called for each node
-    */
-  template <class Tree, class NodeFunc>
-  void forEachNode_(Tree&& tree, NodeFunc&& nodeFunc)
-  {
-    forEachNode_(tree, nodeFunc, nodeFunc);
-  }
-
-  /**
-    * \brief Traverse tree and visit each leaf node
-    *
-    * The passed callback function is called with the
-    * node and corresponding treepath as arguments.
-    *
-    * \param tree The tree to traverse
-    * \param leafFunc This function is called for each leaf node
-    */
-  template <class Tree, class LeafFunc>
-  void forEachLeafNode_(Tree&& tree, LeafFunc&& leafFunc)
-  {
-    auto nop = [](auto&&... args) {};
-    forEachNode_(tree, nop, leafFunc, nop);
-  }
-
-} // end namespace AMDiS

test/DataTransferTest.hpp

@@ -68,7 +68,7 @@ auto makeProblem(typename BasisCreator::GlobalBasis::GridView::Grid& grid, Fcts
 
   // interpolate given function to initial grid
   int k = 0;
-  AMDiS::forEachLeafNode_(localView.tree(), [&](auto const& node, auto tp)
+  for_each_leaf_node(localView.tree(), [&](auto const& node, auto tp)
   {
     interpolate(globalBasis, tp, prob.solution(tp).coefficients(), funcs[k]);
     k++;
@@ -90,7 +90,7 @@ double calcError(Problem const& prob, Fcts const& funcs)
   int k = 0;
 
   // interpolate given function onto reference vector
-  AMDiS::forEachLeafNode_(localView.tree(), [&](auto const& node, auto tp)
+  for_each_leaf_node(localView.tree(), [&](auto const& node, auto tp)
   {
     interpolate(globalBasis, tp, ref, funcs[k]);
     k++;

test/TreeDataTest.cpp

@@ -25,7 +25,7 @@ bool operator==(TreeData<Basis,NodeData,false> const& t1, TreeData<Basis,NodeDat
   AMDIS_TEST(t1.basis() == t2.basis() && t1.basis() != nullptr);
 
   bool same = true;
-  AMDiS::forEachNode_(t1.basis()->localView().tree(), [&](auto const& node, auto) {
+  for_each_node(t1.basis()->localView().tree(), [&](auto const& node, auto) {
     same = same && (t1[node] == t2[node]);
   });
 
@@ -38,7 +38,7 @@ bool operator==(TreeData<Basis,NodeData,true> const& t1, TreeData<Basis,NodeData
   AMDIS_TEST(t1.basis() == t2.basis() && t1.basis() != nullptr);
 
   bool same = true;
-  AMDiS::forEachLeafNode_(t1.basis()->localView().tree(), [&](auto const& node, auto) {
+  for_each_leaf_node(t1.basis()->localView().tree(), [&](auto const& node, auto) {
     same = same && (t1[node] == t2[node]);
   });
 
@@ -73,7 +73,7 @@ int main ()
     TreeData<Basis, NodeData, false> treeData;
     treeData.init(basis);
 
-    AMDiS::forEachNode_(tree, [&](auto const& node, auto) {
+    for_each_node(tree, [&](auto const& node, auto) {
       treeData[node] = double(node.treeIndex());
     });
 
@@ -109,7 +109,7 @@ int main ()
     TreeData<Basis, NodeData, true> treeData;
     treeData.init(basis);
 
-    AMDiS::forEachLeafNode_(tree, [&](auto const& node, auto) {
+    for_each_leaf_node(tree, [&](auto const& node, auto) {
       treeData[node] = double(node.treeIndex());
     });