Disable get_solute_flux_reconstructed at compile-time

Use enable_if instead of run-time exception.

dune/dorie/model/transport/transport.hh

@@ -471,56 +471,49 @@ public:
    *
    * @return     Pointer to a solute grid function
    */
-  std::shared_ptr<const GFFluxReconstruction> get_solute_flux_reconstructed(ConstState state) const
+  template<bool enabled=enable_rt_engine>
+	std::enable_if_t<enabled, std::shared_ptr<const GFFluxReconstruction>>
+  get_solute_flux_reconstructed(ConstState state) const
   {
     std::shared_ptr<GFFluxReconstruction> gf_ptr;
 
     auto& cache = cache_solute_flux_gf_rt;
 
-    if constexpr (enable_rt_engine)
+    if (state.grid_function_space != gfs
+        or state.coefficients != u
+        or state.time != current_time())
     {
+      // if state is different to current state, create flux from zero
 
-      if (state.grid_function_space != gfs or 
-          state.coefficients != u or
-          state.time != current_time())
-      {
-        // if state is different to current state, create flux from zero
+      gf_ptr = std::make_unique<GFFluxReconstruction>(
+                      this->_log,gv,inifile.sub("fluxReconstruction"));
 
-        gf_ptr = std::make_unique<GFFluxReconstruction>(
-                        this->_log,gv,inifile.sub("fluxReconstruction"));
-        
-        slop->setTime(state.time);
+      slop->setTime(state.time);
 
-        // update it with the state
-        gf_ptr->update(*(state.coefficients),
-                       *(state.grid_function_space),
-                       *slop);
+      // update it with the state
+      gf_ptr->update(*(state.coefficients),
+                      *(state.grid_function_space),
+                      *slop);
 
-        slop->setTime(current_time());
-      } else if (not cache) {
-        // if state is equal to current state, use cache.
+      slop->setTime(current_time());
+    } else if (not cache) {
+      // if state is equal to current state, use cache.
 
-        cache = std::make_unique<GFFluxReconstruction>(
-                        this->_log,gv,inifile.sub("fluxReconstruction"));
-        
-        slop->setTime(state.time);
+      cache = std::make_unique<GFFluxReconstruction>(
+                      this->_log,gv,inifile.sub("fluxReconstruction"));
 
-        // update it with current state
-        cache->update(*u,*gfs,*slop);
+      slop->setTime(state.time);
 
-        slop->setTime(current_time());
+      // update it with current state
+      cache->update(*u,*gfs,*slop);
 
-        gf_ptr = cache;
-      } else {
-        gf_ptr = cache;
-      }
+      slop->setTime(current_time());
 
+      gf_ptr = cache;
     } else {
-      DUNE_THROW(NotImplemented, 
-        "Flux reconstruction is not implemented for the selected "
-        << "configuration");
+      gf_ptr = cache;
     }
-    
+
     return gf_ptr;
   }
 
@@ -529,7 +522,9 @@ public:
    *
    * @return     Pointer to a solute grid function
    */
-  std::shared_ptr<const GFFluxReconstruction> get_solute_flux_reconstructed() const
+  template<bool enabled=enable_rt_engine>
+	std::enable_if_t<enabled, std::shared_ptr<const GFFluxReconstruction>>
+  get_solute_flux_reconstructed() const
   {
     return get_solute_flux_reconstructed(current_state());
   }