Merge branch 'issue/order_member_function' into 'master'

allow order() as memberfunction of gridfunctions

See merge request !34

src/amdis/gridfunctions/ConstantGridFunction.hpp

@@ -78,13 +78,6 @@ namespace AMDiS
     return lf.derivative();
   }
 
-  /// \relates ConstantLocalFunction
-  template <class R, class D, class LC, class T>
-  int order(ConstantLocalFunction<R(D), LC, T> const& lf)
-  {
-    return 0;
-  }
-
 
   /// \brief Gridfunction returning a constant value.
   /**

src/amdis/gridfunctions/DiscreteFunction.inc.hpp

@@ -59,10 +59,10 @@ public:
   }
 
   /// \brief The \ref polynomialDegree() of the LocalFunctions
-  friend int order(LocalFunction const& self)
+  int order() const
   {
-    assert( self.bound_ );
-    return polynomialDegree(*self.subTree_);
+    assert( bound_ );
+    return polynomialDegree(*subTree_);
   }
 
   /// \brief Return the bound element
@@ -129,10 +129,10 @@ public:
   /// Evaluate Gradient at bound element in local coordinates
   Range operator()(Domain const& x) const;
 
-  friend int order(GradientLocalFunction const& self)
+  int order() const
   {
-    assert( self.bound_ );
-    return std::max(0, polynomialDegree(*self.subTree_)-1);
+    assert( bound_ );
+    return std::max(0, polynomialDegree(*subTree_)-1);
   }
 
   /// Return the bound element

src/amdis/gridfunctions/GridFunctionConcepts.hpp

@@ -136,6 +136,15 @@ namespace AMDiS
   }
 
 
+  // polynomial order of local functions
+  template <class LocalFunction,
+    class = void_t<decltype(std::declval<LocalFunction>().order())> >
+  int order(LocalFunction const& lf)
+  {
+    return lf.order();
+  }
+
+
 #ifndef DOXYGEN
   template <class PreGridFct, class = void>
   struct GridFunctionCreator

src/amdis/utility/QuadratureFactory.hpp

@@ -40,7 +40,7 @@ namespace AMDiS
 
 
   template <class LF>
-  using HasLocalFunctionOrder = decltype( order(std::declval<LF>()) );
+  using HasLocalFunctionOrder = decltype( AMDiS::order(std::declval<LF>()) );
 
 
   /// \brief Factory for quadrature rule, that calculates the coefficient order from