Move out YGValue

Summary:
@public

Creates a single header file for `YGValue`. This is in preparation of a more compact representation of `YGValue` within `YGStyle`.

Also fixes the incorrect definition of NAN.

Reviewed By: SidharthGuglani

Differential Revision: D13172444

fbshipit-source-id: 4250dbcf8fe15ec3ecdee3913360a73bab633ce3

yoga/YGValue.cpp

@@ -0,0 +1,29 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the LICENSE
+ * file in the root directory of this source tree.
+ */
+#include "YGValue.h"
+
+const YGValue YGValueZero = {0, YGUnitPoint};
+const YGValue YGValueUndefined = {YGUndefined, YGUnitUndefined};
+const YGValue YGValueAuto = {YGUndefined, YGUnitAuto};
+
+bool operator==(const YGValue& lhs, const YGValue& rhs) {
+  if (lhs.unit != rhs.unit) {
+    return false;
+  }
+
+  switch (lhs.unit) {
+    case YGUnitUndefined:
+    case YGUnitAuto:
+      return true;
+    default:
+      return lhs.value == rhs.value;
+  }
+}
+
+bool operator!=(const YGValue& lhs, const YGValue& rhs) {
+  return !(lhs == rhs);
+}

yoga/YGValue.h

@@ -0,0 +1,40 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the LICENSE
+ * file in the root directory of this source tree.
+ */
+#pragma once
+
+#include <math.h>
+#include "YGEnums.h"
+#include "YGMacros.h"
+
+YG_EXTERN_C_BEGIN
+
+// Not defined in MSVC++
+#ifndef NAN
+static const uint32_t __nan = 0x7fc00000;
+#define NAN (*(const float*)__nan)
+#endif
+
+#define YGUndefined NAN
+
+typedef struct YGValue {
+  float value;
+  YGUnit unit;
+} YGValue;
+
+extern const YGValue YGValueAuto;
+extern const YGValue YGValueUndefined;
+extern const YGValue YGValueZero;
+
+YG_EXTERN_C_END
+
+#ifdef __cplusplus
+
+bool operator==(const YGValue& lhs, const YGValue& rhs);
+
+bool operator!=(const YGValue& lhs, const YGValue& rhs);
+
+#endif

yoga/Yoga.cpp

@@ -39,23 +39,6 @@ static int YGDefaultLog(
     va_list args);
 #endif
 
-const YGValue YGValueZero = {0, YGUnitPoint};
-const YGValue YGValueUndefined = {YGUndefined, YGUnitUndefined};
-const YGValue YGValueAuto = {YGUndefined, YGUnitAuto};
-
-bool operator==(const YGValue& lhs, const YGValue& rhs) {
-  if ((lhs.unit == YGUnitUndefined && rhs.unit == YGUnitUndefined) ||
-      (lhs.unit == YGUnitAuto && rhs.unit == YGUnitAuto)) {
-    return true;
-  }
-
-  return lhs.unit == rhs.unit && lhs.value == rhs.value;
-}
-
-bool operator!=(const YGValue& lhs, const YGValue& rhs) {
-  return !(lhs == rhs);
-}
-
 #ifdef ANDROID
 #include <android/log.h>
 static int YGAndroidLog(

yoga/Yoga.h

@@ -17,16 +17,9 @@
 #include <stdbool.h>
 #endif
 
-// Not defined in MSVC++
-#ifndef NAN
-static const unsigned long __nan[2] = {0xffffffff, 0x7fffffff};
-#define NAN (*(const float*)__nan)
-#endif
-
-#define YGUndefined NAN
-
 #include "YGEnums.h"
 #include "YGMacros.h"
+#include "YGValue.h"
 
 YG_EXTERN_C_BEGIN
 
@@ -35,25 +28,6 @@ typedef struct YGSize {
   float height;
 } YGSize;
 
-typedef struct YGValue {
-  float value;
-  YGUnit unit;
-} YGValue;
-
-extern const YGValue YGValueUndefined;
-extern const YGValue YGValueAuto;
-
-#ifdef __cplusplus
-
-YG_EXTERN_C_END
-
-extern bool operator==(const YGValue& lhs, const YGValue& rhs);
-extern bool operator!=(const YGValue& lhs, const YGValue& rhs);
-
-YG_EXTERN_C_BEGIN
-
-#endif
-
 typedef struct YGConfig* YGConfigRef;
 
 typedef struct YGNode* YGNodeRef;