Add Thrift Patch support for cpp.Type of std::unique_ptr<folly::IOBuf>

Summary: Add support for `cpp.type = std::unique_ptr<folly::IOBuf>`. This type is special in Thrift where it expects to work with all features provided by Thrift.

Reviewed By: Mizuchi

Differential Revision: D70417418

fbshipit-source-id: c1cc8ec77c0ebed66b3725ea4ed2ae9f016f9be4

thrift/lib/cpp2/op/detail/StructPatch.h

@@ -367,6 +367,12 @@ class BaseEnsurePatch : public BaseClearPatch<Patch, Derived> {
       }
     }
   }
+  template <typename Id>
+  std::enable_if_t<type::is_optional_or_union_field_v<T, Id>> ensure(
+      const std::unique_ptr<folly::IOBuf>& defaultVal) {
+    ensure(std::make_unique<folly::IOBuf>(*defaultVal));
+  }
+
   /// Ensures the given field is initalized, and return the associated patch
   /// object.
   template <class Id>

thrift/lib/cpp2/op/detail/ValuePatch.h

@@ -375,6 +375,8 @@ class BinaryPatch : public BaseStringPatch<Patch, BinaryPatch<Patch>> {
   void assign(std::string s) {
     assign(*folly::IOBuf::fromString(std::move(s)));
   }
+  void assign(std::unique_ptr<folly::IOBuf>&& s) { assign(std::move(*s)); }
+  void assign(const std::unique_ptr<folly::IOBuf>& s) { assign(*s); }
 
   template <typename T>
   BinaryPatch& operator=(T&& other) {
@@ -427,6 +429,13 @@ class BinaryPatch : public BaseStringPatch<Patch, BinaryPatch<Patch>> {
     val = buf->toString();
   }
 
+  void apply(std::unique_ptr<folly::IOBuf>& val) const {
+    if (!val) {
+      val = std::make_unique<folly::IOBuf>();
+    }
+    apply(*val);
+  }
+
  private:
   using Base::assignOr;
   using Base::data_;