Merge branch 'make-functions-copyable' of...

Merge branch 'make-functions-copyable' of zivgitlab.uni-muenster.de:ag-ohlberger/dune-community/dune-xt into fix_compilation_with_icc

dune/xt/common/tuple.hh

@@ -370,7 +370,7 @@ using tuple_tail_t = typename list_content<T1>::tail;
 
 /** These classes allow recursively visiting a typelist that may contain templates names
  *  So if you ever wanted to iterate over "AllDirichletBoundaryInfo, AllNeumannBoundaryInfo, etc"
- *  and then input another type as tpl arg, sthis is for you.
+ *  and then input another type as tpl arg, this is for you.
  *
  * **/
 
@@ -448,9 +448,23 @@ public:
   using head_type = typename internal::head_hlp<tuple_head_t<type<T...>>>::type;
 };
 
+template <typename Head, typename... Tail>
+struct list_content<template_tuple<Head, Tail...>>
+{
+  template <class... Parameters>
+  using head = typename internal::from_tplwrap<Head, Parameters...>::type;
+  using tail = template_tuple<Tail...>;
+};
 
-using null_template_tuple = template_tuple<Dune::XT::Common::tuple_null_type>;
+template <typename T>
+struct list_content<template_tuple<T>>
+{
+  template <class... Parameters>
+  using head = typename internal::from_tplwrap<T, Parameters...>::type;
+  using tail = tuple_null_type;
+};
 
+using null_template_tuple = template_tuple<Dune::XT::Common::tuple_null_type>;
 
 template <typename... input_t>
 using tuple_cat_t = decltype(std::tuple_cat(std::declval<input_t>()...));
@@ -459,4 +473,12 @@ using tuple_cat_t = decltype(std::tuple_cat(std::declval<input_t>()...));
 } // namespace XT
 } // namespace Dune
 
+namespace std {
+//! specialization for our custom tuple tuple_size can be use on it
+template <class... Types>
+class tuple_size<Dune::XT::Common::template_tuple<Types...>>
+  : public std::integral_constant<std::size_t, sizeof...(Types)>
+{};
+
+} // namespace std
 #endif // DUNE_XT_COMMON_TUPLE_HH

dune/xt/test/common/tuple.cc

@@ -80,14 +80,22 @@ struct tplB
 template <class Tuple>
 void type_call()
 {
-  using TupleElement = typename Dune::XT::Common::list_content<Tuple>::template head<int, int>;
-  using Type = typename TupleElement::type;
-  static_assert(std::is_same<Type, int>::value, "");
-  using Tail = typename Tuple::template tail_type<int, int>;
+  if constexpr (std::tuple_size_v<Tuple> == 3) {
+    using TupleElement = typename Dune::XT::Common::list_content<Tuple>::template head<int, int>;
+    using Type = typename TupleElement::type;
+    static_assert(std::is_same<TupleElement, tplA<int, int>>::value, "");
+    static_assert(std::is_same<Type, int>::value, "");
+  } else if constexpr (std::tuple_size_v<Tuple> == 2) {
+    using TupleElement = typename Dune::XT::Common::list_content<Tuple>::template head<int, int>;
+    using Type = typename TupleElement::type;
+    static_assert(std::is_same<TupleElement, tplB<int, int>>::value, "");
+    static_assert(std::is_same<Type, int>::value, "");
+  } else if constexpr (std::tuple_size_v<Tuple> == 1) {
+    using TupleElement = typename Dune::XT::Common::list_content<Tuple>::template head<int, int>;
+    static_assert(std::is_same<TupleElement, int>::value, "");
+  }
 
-  // do something meaningful with a single type
-  EXPECT_EQ(Type(0), int(0));
-  EXPECT_EQ(Type(0.2), int(0.2));
+  using Tail = typename Tuple::template tail_type<int, int>;
   type_call<Tail>();
 }