Add constructor that only sets the solver parameter

dune/solvers/solvers/quadraticipopt.hh

@@ -650,6 +650,12 @@ public:
                               constraintObstacles_(nullptr),constraintMatrix_(nullptr)
     {}
 
+    /** \brief Constructor that only sets solver parameter. */
+    QuadraticIPOptSolver (field_type tolerance, int numIterations,
+                    NumProc::VerbosityMode verbosity = NumProc::FULL)
+        : IterativeSolver<VectorType>(tolerance, numIterations, verbosity)
+     {}
+
     /** \brief Constructor for a linear problem */
     QuadraticIPOptSolver (const MatrixType& hessian,
                        VectorType& x,