Make compatible with Alpine linux by using cmath instead of math.h

Author: toddbluhm

src/platformcompat.hh

@@ -1,8 +1,6 @@
 #ifndef __PLATFORMCOMPAT_H
 #define __PLATFORMCOMPAT_H
 
-#include <math.h> // round()
-
 #if defined(_MSC_VER)
 #include <float.h> //isinf, isnan
 #include <stdlib.h> //min
@@ -11,10 +9,11 @@
 #define FMIN __min
 #define ROUND(x) floor(x + 0.5)
 #else
-#define ISINF isinf
-#define ISNAN isnan
+#include <cmath> // round(), isinf, isnan
+#define ISINF std::isinf
+#define ISNAN std::isnan
 #define FMIN fmin
 #define ROUND round
 #endif
 
-#endif
+#endif