Replace result of_t by invoke_result_t

dune/curvedgrid/gridfunctions/analyticdiscretefunction.hh

@@ -48,7 +48,7 @@ public:
   using ctype = typename Geometry::ctype;
 
   using Domain = typename Geometry::GlobalCoordinate;
-  using RangeType = std::result_of_t<Functor(Domain)>;
+  using RangeType = std::invoke_result_t<Functor,Domain>;
 
   template <int degree>
   using DerivativeRange = typename Impl::DerivativeRangeType<RangeType(Domain), degree, Functions::DefaultDerivativeTraits>::type;
@@ -228,7 +228,7 @@ public:
   using EntitySet = GridEntitySet<Grid,0>;
 
   using Domain = typename EntitySet::GlobalCoordinate;
-  using Range = std::result_of_t<Functor(Domain)>;
+  using Range = std::invoke_result_t<Functor,Domain>;
   using Signature = Range(Domain);
 
 public: