Implement AssignPatch::toSafePatch

Reviewed By: pranavtbhat

Differential Revision: D66671131

fbshipit-source-id: 3216c9f05988c0f92d7462eed90efdcccb523afd

third-party/thrift/src/thrift/lib/cpp2/op/AssignPatch.h

@@ -20,7 +20,7 @@
 
 #include <folly/json.h>
 #include <folly/logging/xlog.h>
-#include <thrift/lib/cpp2/op/detail/BasePatch.h>
+#include <thrift/lib/cpp2/op/Patch.h>
 #include <thrift/lib/cpp2/protocol/Patch.h>
 
 namespace apache::thrift {
@@ -138,6 +138,17 @@ class AssignPatch : public BaseAssignPatch<Patch, AssignPatch<Patch>> {
     Base::reset();
   }
 
+  template <class..., bool IsStructured = is_thrift_class_v<T>>
+  static auto fromSafePatch(
+      const typename std::enable_if_t<IsStructured, SafePatchType<Tag>>::type&
+          safePatch) {
+    return fromSafePatchImpl<AssignPatch>(safePatch);
+  }
+
+  auto toSafePatch() const {
+    return toSafePatchImpl<typename SafePatchType<Tag>::type>(*this);
+  }
+
  private:
   using Base::data_;
   std::optional<protocol::Object> dynPatch_;

third-party/thrift/src/thrift/lib/cpp2/op/detail/PatchTraits.h

@@ -107,6 +107,10 @@ template <class>
 constexpr inline bool is_any_patch_v = false;
 template <class Patch>
 constexpr inline bool is_any_patch_v<AnyPatch<Patch>> = true;
+template <class>
+constexpr inline bool is_assign_patch_v = false;
+template <class Patch>
+constexpr inline bool is_assign_patch_v<AssignPatch<Patch>> = true;
 
 class MinSafePatchVersionVisitor {
  public:
@@ -170,9 +174,13 @@ class MinSafePatchVersionVisitor {
 template <typename Patch>
 int32_t calculateMinSafePatchVersion(const Patch& patch) {
   // is_patch_v
-  MinSafePatchVersionVisitor visitor;
-  patch.customVisit(visitor);
-  return visitor.version;
+  if constexpr (is_assign_patch_v<Patch>) {
+    return 1;
+  } else {
+    MinSafePatchVersionVisitor visitor;
+    patch.customVisit(visitor);
+    return visitor.version;
+  }
 }
 
 } // namespace apache::thrift::op::detail