[orc-rt] Add SPS serialization support for size_t.

orc-rt/include/orc-rt/SimplePackedSerialization.h

@@ -172,6 +172,28 @@ class SPSSerializationTraits<
   }
 };
 
+class SPSSize;
+
+/// SPSSize is serializable to/from size_t. Wire size is 64-bits.
+template <> class SPSSerializationTraits<SPSSize, size_t> {
+public:
+  static size_t size(const size_t &Value) {
+    return SPSArgList<uint64_t>::size(static_cast<uint64_t>(Value));
+  }
+  static bool serialize(SPSOutputBuffer &OB, const size_t &Value) {
+    return SPSArgList<uint64_t>::serialize(OB, static_cast<uint64_t>(Value));
+  }
+  static bool deserialize(SPSInputBuffer &IB, size_t &Value) {
+    uint64_t Tmp;
+    if (!SPSArgList<uint64_t>::deserialize(IB, Tmp))
+      return false;
+    if (Tmp > std::numeric_limits<size_t>::max())
+      return false;
+    Value = Tmp;
+    return true;
+  }
+};
+
 /// Any empty placeholder suitable as a substitute for void when deserializing
 class SPSEmpty {};
 

orc-rt/unittests/SimplePackedSerializationTest.cpp

@@ -103,6 +103,11 @@ TEST(SimplePackedSerializationTest, UInt64Serialization) {
   testFixedIntegralTypeSerialization<uint64_t>();
 }
 
+TEST(SimplePackedSerializationTest, SizeTSerialization) {
+  size_t V = 42;
+  blobSerializationRoundTrip<SPSSize, size_t>(V);
+}
+
 TEST(SimplePackedSerializationTest, SequenceSerialization) {
   std::vector<int32_t> V({1, 2, -47, 139});
   blobSerializationRoundTrip<SPSSequence<int32_t>, std::vector<int32_t>>(V);