[common] allow adl for math functions

(cherry picked from commit 3b9e129a)

dumux/common/boundingboxtree.hh

@@ -251,7 +251,8 @@ public:
         // first check if we are in the plane of the triangle
         // if not we can return early
         const double t = v.dot(n);
-        if (std::abs(t) > v1.two_norm()*eps_) // take |v1| as scale
+        using std::abs;
+        if (abs(t) > v1.two_norm()*eps_) // take |v1| as scale
             return false;
 
         // compute the normal to the triangle made of point and first edge
@@ -691,7 +692,8 @@ public:
         // small than the interval length and the
         // sign of v1 & v2 are the same
         using std::abs;
-        return (std::signbit(v1) == std::signbit(v2)
+        using std::signbit;
+        return (signbit(v1) == signbit(v2)
                 && abs(v1) < abs(v2)*(1 + eps_));
     }
 

dumux/common/eigenvalues.hh

@@ -72,6 +72,7 @@ bool calculateEigenValues(EVVectorType &eigVel, MatrixType& matrix, double relat
         double b = -(matrix[0][0] + matrix[1][1]);
         double c = matrix[0][0] * matrix[1][1] - matrix[0][1] * matrix[1][0];
 
+        using std::sqrt;
         eigVel[0] = (-b + sqrt(b * b - 4.0 * c)) / 2.0;
         eigVel[1] = (-b - sqrt(b * b - 4.0 * c)) / 2.0;
 

dumux/common/geometrycollision.hh

@@ -125,7 +125,8 @@ public:
 
             // if denominator is zero the segment in parallel to
             // the plane. If the distance is positive there is no intersection
-            if (std::abs(denom) < eps)
+            using std::abs;
+            if (abs(denom) < eps)
             {
                 if (dist > eps)
                     return false;
@@ -134,7 +135,8 @@ public:
             {
                 const Scalar t = -dist / denom;
                 // if entering half space cut tfirst if t is larger
-                if (std::signbit(denom))
+                using std::signbit;
+                if (signbit(denom))
                 {
                     if (t > tfirst)
                         tfirst = t;