Extract some concepts from Vtk::Function

dune/vtk/function.hh

@@ -9,6 +9,7 @@
 #include <dune/vtk/localfunction.hh>
 #include <dune/vtk/types.hh>
 #include <dune/vtk/utility/arguments.hh>
+#include <dune/vtk/utility/concepts.hh>
 
 namespace Dune
 {
@@ -28,16 +29,6 @@ namespace Dune
       using Element = typename GridView::template Codim<0>::Entity;
       using LocalDomain = typename Element::Geometry::LocalCoordinate;
 
-      template <class GF>
-      using IsGridFunction = decltype(localFunction(std::declval<GF>()));
-
-      template <class LocalFunction, class LF = std::decay_t<LocalFunction>>
-      using IsLocalFunction = decltype((
-        std::declval<LF&>().bind(std::declval<Element>()),
-        std::declval<LF&>().unbind(),
-        std::declval<LF>()(std::declval<LocalDomain>()),
-      0));
-
       template <class F, class D>
       using Range = std::decay_t<std::result_of_t<F(D)>>;
 
@@ -67,15 +58,15 @@ namespace Dune
       * \param localFct    A local-function, providing a `bind(Element)` and an `operator()(LocalDomain)`
       * \param name        The name to use as identification in the VTK file
       * \param components  A vector of component indices to extract from the range type
-      * \param category    The \ref Vtk::RangeTypes category for the range. [Vtk::RangeTypes::AUTO]
-      * \param dataType    The \ref Vtk::DataTypes used in the output. [Vtk::DataTypes::FLOAT32]
+      * \param category    The \ref Vtk::RangeTypes category for the range. [Vtk::RangeTypes::UNSPECIFIED]
+      * \param dataType    The \ref Vtk::DataTypes used in the output. [Vtk::DataTypes::FLOAT64]
       *
       * The arguments `category` and `dataType` can be passed in any order.
       *
       * NOTE: Stores the localFunction by value.
       **/
       template <class LF, class... Args,
-        class = IsLocalFunction<LF>>
+        IsLocalFunction<LF,Element> = true>
       Function (LF&& localFct, std::string name, std::vector<int> components, Args&&... args)
         : localFct_(std::forward<LF>(localFct))
         , name_(std::move(name))
@@ -97,7 +88,7 @@ namespace Dune
       * NOTE: Stores the localFunction by value.
       **/
       template <class LF, class... Args,
-        class = IsLocalFunction<LF>>
+        IsLocalFunction<LF,Element> = true>
       Function (LF&& localFct, std::string name, int ncomps, Args&&... args)
         : Function(std::forward<LF>(localFct), std::move(name), allComponents(ncomps),
                    std::forward<Args>(args)...)
@@ -110,7 +101,7 @@ namespace Dune
        * static size information could be extracted.
        **/
       template <class LF, class... Args,
-        class = IsLocalFunction<LF>,
+        IsLocalFunction<LF,Element> = true,
         class R = Range<LF,LocalDomain> >
       Function (LF&& localFct, std::string name, Args&&... args)
         : Function(std::forward<LF>(localFct), std::move(name), sizeOf<R>(),
@@ -138,7 +129,7 @@ namespace Dune
       */
       template <class GF, class... Args,
         disableCopyMove<Function, GF> = 0,
-        class = IsGridFunction<GF> >
+        IsGridFunction<GF> = true>
       Function (GF&& fct, std::string name, Args&&... args)
         : Function(localFunction(std::forward<GF>(fct)), std::move(name), std::forward<Args>(args)...)
       {}
@@ -149,10 +140,10 @@ namespace Dune
         : Function(std::forward<F>(fct), info.name(), info.size(), info.rangeType(), info.dataType())
       {}
 
-      /// (6) Automatically extract name and num components from GridFunction if available
+      /// (7) Automatically extract name and num components from GridFunction if available
       template <class F, class... Args,
         disableCopyMove<Function, F> = 0,
-        class = decltype(localFunction(std::declval<F>())),
+        IsGridFunction<F> = true,
         class = decltype(std::declval<F>().name()),
         class = decltype(std::declval<F>().numComponents()),
         class = decltype(std::declval<F>().dataType()) >
@@ -161,8 +152,7 @@ namespace Dune
                    Vtk::RangeTypes::UNSPECIFIED, fct.dataType())
       {}
 
-
-      /// (7) Construct from legacy VTKFunction
+      /// (8) Construct from legacy VTKFunction
       /**
       * \param fct  The Dune::VTKFunction to wrap
       **/
@@ -175,7 +165,7 @@ namespace Dune
         setRangeType(rangeTypeOf(fct->ncomps()));
       }
 
-      /// (8) Default constructor. After construction, the function is an an invalid state.
+      /// (9) Default constructor. After construction, the function is an an invalid state.
       Function () = default;
 
       /// Create a LocalFunction

dune/vtk/utility/concepts.hh

@@ -26,5 +26,17 @@ namespace Dune
       CheckTypes<typename GV::Grid, typename GV::IndexSet>{},
     true));
 
+    template <class GridFunction, class GF = std::decay_t<GridFunction>>
+    using IsGridFunction = decltype((
+      localFunction(std::declval<GF const&>()),
+    true));
+
+    template <class LocalFunction, class LocalContext, class LF = std::decay_t<LocalFunction>>
+    using IsLocalFunction = decltype((
+      std::declval<LF&>().bind(std::declval<LocalContext>()),
+      std::declval<LF&>().unbind(),
+      std::declval<LF>()(std::declval<typename LocalContext::Geometry::LocalCoordinate>()),
+    true));
+
   } // end namespace Vtk
 } // end namespace Dune