fix compile

Numeric/MetricBasis.cpp

@@ -1133,7 +1133,7 @@ double MetricBasis::_subdivideForRmin(
 
   md = subdomains.top();
   double ans = md->_RminBez;
-  if (isnan(ans)) Msg::Error("ISNAN %d", subdomains.size());
+  if (std::isnan(ans)) Msg::Error("ISNAN %d", subdomains.size());
 
   while (subdomains.size()) {
     md = subdomains.top();

Numeric/MetricBasis.h

@@ -113,7 +113,7 @@ private:
     const double phi = std::acos(x) / 3;
     return (a + 2*std::cos(phi + 2*M_PI/3)) / (a + 2*std::cos(phi));
   }
-  bool _chknumber(double val) const {return isnan(val) || isinf(val);}
+  bool _chknumber(double val) const {return std::isnan(val) || std::isinf(val);}
   bool _chka(double a) const {return _chknumber(a) || a < 1;}
   bool _chkK(double K) const {return _chknumber(K) || K < 0;}
   int _chkaK(double a, double K) const {