Move reset logic to YGNode::reset()

Summary:
@public

Moving logic from free C functions to the C++ layer.

This will allow us to get rid of the dangerous copy / move assignment operators of `YGNode`.

Reviewed By: SidharthGuglani

Differential Revision: D14241564

fbshipit-source-id: aae9f2a7ffd23bb839f1747e4a0694578bae86ae

yoga/YGNode.cpp

@@ -571,3 +571,22 @@ bool YGNode::isLayoutTreeEqualToNode(const YGNode& node) const {
   }
   return isLayoutTreeEqual;
 }
+
+void YGNode::reset() {
+  YGAssertWithNode(
+      this,
+      children_.size() == 0,
+      "Cannot reset a node which still has children attached");
+  YGAssertWithNode(
+      this, owner_ == nullptr, "Cannot reset a node still attached to a owner");
+
+  clearChildren();
+
+  auto config = getConfig();
+  *this = YGNode{};
+  if (config->useWebDefaults) {
+    setStyleFlexDirection(YGFlexDirectionRow);
+    setStyleAlignContent(YGAlignStretch);
+  }
+  setConfig(config);
+}

yoga/YGNode.h

@@ -342,4 +342,5 @@ public:
   bool isNodeFlexible();
   bool didUseLegacyFlag();
   bool isLayoutTreeEqualToNode(const YGNode& node) const;
+  void reset();
 };

yoga/Yoga.cpp

@@ -323,25 +323,8 @@ void YGNodeFreeRecursive(const YGNodeRef root) {
   return YGNodeFreeRecursiveWithCleanupFunc(root, nullptr);
 }
 
-void YGNodeReset(const YGNodeRef node) {
+void YGNodeReset(YGNodeRef node) {
-  YGAssertWithNode(
+  node->reset();
-      node,
-      YGNodeGetChildCount(node) == 0,
-      "Cannot reset a node which still has children attached");
-  YGAssertWithNode(
-      node,
-      node->getOwner() == nullptr,
-      "Cannot reset a node still attached to a owner");
-
-  node->clearChildren();
-
-  const YGConfigRef config = node->getConfig();
-  *node = YGNode();
-  if (config->useWebDefaults) {
-    node->setStyleFlexDirection(YGFlexDirectionRow);
-    node->setStyleAlignContent(YGAlignStretch);
-  }
-  node->setConfig(config);
 }
 
 int32_t YGNodeGetInstanceCount(void) {