attempt to fix VC++ comilation error.

implemented move constructor explicitly.

ProcessLib/ProcessVariable.cpp

@@ -95,6 +95,14 @@ ProcessVariable::ProcessVariable(
     }
 }
 
+ProcessVariable::ProcessVariable(ProcessVariable&& other)
+    : _name(std::move(other._name)),
+      _mesh(other._mesh),
+      _initial_condition(std::move(other._initial_condition)),
+      _dirichlet_bcs(std::move(other._dirichlet_bcs)),
+      _neumann_bc_configs(std::move(other._neumann_bc_configs))
+{}
+
 std::string const& ProcessVariable::getName() const
 {
     return _name;

ProcessLib/ProcessVariable.h

@@ -52,7 +52,7 @@ public:
     ProcessVariable(ConfigTree const& config, MeshLib::Mesh const& mesh,
             GeoLib::GEOObjects const& geometries);
 
-    ProcessVariable(ProcessVariable&&) = default; // maybe circumvents VC++ compilation errors in combination with std::vector
+    ProcessVariable(ProcessVariable&&); // maybe circumvents VC++ compilation errors in combination with std::vector
 
     std::string const& getName() const;