Fixed initialization of pointers in SemiImplicitTimeStepper

src/TNL/Solvers/PDE/SemiImplicitTimeStepper.h

@@ -70,18 +70,18 @@ class SemiImplicitTimeStepper
 
    protected:
 
+   // raw pointers with setters
    Problem* problem = nullptr;
+   SolverMonitorType* solverMonitor = nullptr;
 
-   MatrixPointer matrix = nullptr;
-
-   DofVectorPointer rightHandSidePointer = nullptr;
+   // smart pointers initialized to the default-created objects
+   MatrixPointer matrix;
+   DofVectorPointer rightHandSidePointer;
 
+   // uninitialized smart pointers (they are initialized in the setup method)
    LinearSolverPointer linearSystemSolver = nullptr;
-
    PreconditionerPointer preconditioner = nullptr;
 
-   SolverMonitorType* solverMonitor = nullptr;
-
    RealType timeStep = 0.0;
 
    Timer preIterateTimer, linearSystemAssemblerTimer, preconditionerUpdateTimer, linearSystemSolverTimer, postIterateTimer;