Fix visitHierarchy

Author: franzpoeschel

include/openPMD/Iteration.hpp

@@ -273,7 +273,7 @@ class Iteration
     closedByWriter() const;
 
     template <typename Visitor>
-    void visitHierarchy(Visitor &v)
+    void visitHierarchy(Visitor &&v)
     {
         v(*this);
         meshes.visitHierarchy(v);

include/openPMD/ParticleSpecies.hpp

@@ -46,7 +46,7 @@ class ParticleSpecies
     ParticlePatches particlePatches;
 
     template <typename Visitor>
-    void visitHierarchy(Visitor &v)
+    void visitHierarchy(Visitor &&v)
     {
         Container<Record>::visitHierarchy(v);
         particlePatches.visitHierarchy(v);

include/openPMD/RecordComponent.hpp

@@ -487,7 +487,7 @@ class RecordComponent
         std::declval<RecordComponent &>(), std::forward<Args>(args)...));
 
     template <typename Visitor>
-    void visitHierarchy(Visitor &v)
+    void visitHierarchy(Visitor &&v)
     {
         v(*this);
     }

include/openPMD/Series.hpp

@@ -779,7 +779,7 @@ class Series : public Attributable
     void close();
 
     template <typename Visitor>
-    void visitHierarchy(Visitor &v)
+    void visitHierarchy(Visitor &&v)
     {
         v(*this);
         get().iterations.visitHierarchy(v);

include/openPMD/backend/Container.hpp

@@ -263,7 +263,7 @@ class Container : virtual public Attributable
     }
 
     template <typename Visitor>
-    void visitHierarchy(Visitor &v)
+    void visitHierarchy(Visitor &&v)
     {
         v(*this);
         for (auto &p : *this)

include/openPMD/backend/MeshRecordComponent.hpp

@@ -95,7 +95,7 @@ class MeshRecordComponent : public RecordComponent
     MeshRecordComponent &makeConstant(T);
 
     template <typename Visitor>
-    void visitHierarchy(Visitor &v)
+    void visitHierarchy(Visitor &&v)
     {
         v(*this);
     }

include/openPMD/backend/PatchRecordComponent.hpp

@@ -90,7 +90,7 @@ class PatchRecordComponent : public RecordComponent
     void store(T);
 
     template <typename Visitor>
-    void visitHierarchy(Visitor &v)
+    void visitHierarchy(Visitor &&v)
     {
         v(*this);
     }