Make nlevels const in Bisection

src/Bisection.C

@@ -74,7 +74,8 @@ int walsh(int l, int n, int i)
 }
 
 ////////////////////////////////////////////////////////////////////////////////
-Bisection::Bisection(const SlaterDet& sd, int nlevels[3]) : ctxt_(sd.context())
+Bisection::Bisection(const SlaterDet& sd, const int nlevels[3])
+  : ctxt_(sd.context())
 {
   // localization vectors are long int
   assert(sizeof(long int) >= 4);

src/Bisection.h

@@ -69,7 +69,7 @@ class Bisection
 
   public:
 
-    Bisection(const SlaterDet& sd, int nlevels[3]);
+    Bisection(const SlaterDet& sd, const int nlevels[3]);
     void compute_transform(const SlaterDet& sd, int maxsweep, double tol);
     void compute_localization(double epsilon);
     void forward(SlaterDet& sd);