Move all recursive algorithms to algorithm subdirectory

amdis/algorithm/Map.hpp

+#pragma once
+
+#include <array>
+#include <tuple>
+#include <vector>
+
+#include <dune/common/tuplevector.hh>
+#include <amdis/common/Apply.hpp>
+
+namespace AMDiS {
+namespace Recursive {
+
+template <class T>
+struct Map;
+
+/// \brief Recursive application of a transformation functor `f` to a hierarchic
+/// container of containers, returning the transformed container.
+/**
+ * This utility function applies the given functor `f` to the "leaf" entries in
+ * a hierarchic container that returns a transformed container. Therefore, the
+ * container is traversed recursively, using specializations of the `Map<Container>::impl`
+ * class method. If no specialization is provided, the function is applied to the
+ * whole container or leaf entry, respectively.
+ **/
+template <class F, class T>
+auto map(F&& f, T const& t)
+{
+  return Map<T>::impl(f,t);
+}
+
+
+// specializations for container types
+
+/// Default implementation of the recursive \ref map function.
+template <class T>
+struct Map
+{
+  template <class F>
+  static auto impl(F&& f, T const& t)
+  {
+    return f(t);
+  }
+};
+
+template <class T, std::size_t n>
+struct Map<std::array<T,n>>
+{
+  template <class F>
+  static auto impl(F&& f, std::array<T,n> const& a)
+  {
+    return Ranges::applyIndices<n>([&](auto... ii) {
+      return std::array{Recursive::map(f,a[ii])...}; });
+  }
+};
+
+template <class... TT>
+struct Map<std::tuple<TT...>>
+{
+  template <class F>
+  static auto impl(F&& f, std::tuple<TT...> const& t)
+  {
+    return Ranges::apply([&](auto const&... ti) {
+      return std::tuple{Recursive::map(f,ti)...}; }, t);
+  }
+};
+
+template <class T1, class T2>
+struct Map<std::pair<T1,T2>>
+{
+  template <class F>
+  static auto impl(F&& f, std::pair<T1,T2> const& t)
+  {
+    return std::pair{Recursive::map(f,t.first), Recursive::map(f,t.second)};
+  }
+};
+
+template <class... TT>
+struct Map<Dune::TupleVector<TT...>>
+{
+  template <class F>
+  static auto impl(F&& f, Dune::TupleVector<TT...> const& t)
+  {
+    return Ranges::apply([&](auto const&... ti) {
+      return Dune::makeTupleVector(Recursive::map(f,ti)...); }, t);
+  }
+};
+
+template <class T>
+struct Map<std::vector<T>>
+{
+  template <class F>
+  static auto impl(F&& f, std::vector<T> const& v)
+  {
+    using U = TYPEOF(Recursive::map(f,std::declval<T>()));
+    std::vector<U> out;
+    out.reserve(v.size());
+    for (std::size_t i = 0; i < v.size(); ++i)
+      out.emplace_back(Recursive::map(f,v[i]));
+    return out;
+  }
+};
+
+}} // end namespace AMDiS::Recursive