1 files changed, 12 insertions, 15 deletions
diff --git a/include/ceres/fpclassify.h b/include/ceres/fpclassify.h
index b730832..da8a4d0 100644
--- a/include/ceres/fpclassify.h
+++ b/include/ceres/fpclassify.h
@@ -46,25 +46,24 @@
 namespace ceres {
 
 #if defined(_MSC_VER)
-inline bool IsFinite  (double x) { return _finite(x);                }
-inline bool IsInfinite(double x) { return !_finite(x) && !_isnan(x); }
-inline bool IsNaN     (double x) { return _isnan(x);                 }
+
+inline bool IsFinite  (double x) { return _finite(x) != 0;                   }
+inline bool IsInfinite(double x) { return _finite(x) == 0 && _isnan(x) == 0; }
+inline bool IsNaN     (double x) { return _isnan(x) != 0;                    }
 inline bool IsNormal  (double x) {
   int classification = _fpclass(x);
   return classification == _FPCLASS_NN ||
          classification == _FPCLASS_PN;
 }
-#elif defined(ANDROID)
 
-// On Android when using the GNU STL, the C++ fpclassify functions are not
-// available. Strictly speaking, the std functions are are not standard until
-// C++11. Instead use the C99 macros on Android.
+#elif defined(ANDROID) && defined(_STLPORT_VERSION)
+
+// On Android, when using the STLPort, the C++ isnan and isnormal functions
+// are defined as macros.
 inline bool IsNaN     (double x) { return isnan(x);    }
 inline bool IsNormal  (double x) { return isnormal(x); }
-
 // On Android NDK r6, when using STLPort, the isinf and isfinite functions are
 // not available, so reimplement them.
-#  if defined(_STLPORT_VERSION)
 inline bool IsInfinite(double x) {
   return x ==  std::numeric_limits<double>::infinity() ||
          x == -std::numeric_limits<double>::infinity();
@@ -72,17 +71,15 @@ inline bool IsInfinite(double x) {
 inline bool IsFinite(double x) {
   return !isnan(x) && !IsInfinite(x);
 }
-#  else
-inline bool IsFinite  (double x) { return isfinite(x); }
-inline bool IsInfinite(double x) { return isinf(x);    }
-#  endif  // defined(_STLPORT_VERSION)
-#else
+
+# else
+
 // These definitions are for the normal Unix suspects.
-// TODO(keir): Test the "else" with more platforms.
 inline bool IsFinite  (double x) { return std::isfinite(x); }
 inline bool IsInfinite(double x) { return std::isinf(x);    }
 inline bool IsNaN     (double x) { return std::isnan(x);    }
 inline bool IsNormal  (double x) { return std::isnormal(x); }
+
 #endif
 
 }  // namespace ceres