more tests on optional serialization

gtsam/base/std_optional_serialization.h

@@ -1,6 +1,7 @@
-// A hack to serialize std::optional<T> to boost::archive
+// Functionality to serialize std::optional<T> to boost::archive
-// Don't know if it will work. Trying to follow this:
+// Following this:
 // PR: https://github.com/boostorg/serialization/pull/148/files#
+
 #pragma once
 #include <optional>
 #include <boost/config.hpp>

gtsam/base/tests/testStdOptionalSerialization.cpp

@@ -60,6 +60,10 @@ public:
   TestOptionalStruct() = default;
   TestOptionalStruct(const int& opt)
       : opt(opt) {}
+  bool operator==(const TestOptionalStruct& other) const {
+    // check the values are equal
+    return *opt == *other.opt;
+  }
   friend class boost::serialization::access;
   template <class Archive>
   void serialize(Archive& ar, const unsigned int /*version*/) {
@@ -104,6 +108,47 @@ TEST(StdOptionalSerialization, SerializTestOptionalStructUninitialized) {
   EXPECT(serializationTestHelpers::equalsXML(optStruct));
   EXPECT(serializationTestHelpers::equalsBinary(optStruct));
 }
+
+// Test for serialization of std::optional<TestOptionalStruct> 
+TEST(StdOptionalSerialization, SerializTestOptionalStructPointer) {
+  // Create an optional
+  std::optional<TestOptionalStruct> opt(TestOptionalStruct(42));
+
+  // Serialize it
+  std::stringstream ss;
+  boost::archive::text_oarchive oa(ss);
+  oa << opt;
+
+  // Deserialize it
+  std::optional<TestOptionalStruct> opt2;
+  boost::archive::text_iarchive ia(ss);
+  ia >> opt2;
+
+  // Check that it worked
+  EXPECT(opt2.has_value());
+  EXPECT(*opt2 == TestOptionalStruct(42));
+}
+
+// Test for serialization of std::optional<TestOptionalStruct*>
+TEST(StdOptionalSerialization, SerializTestOptionalStructPointerPointer) {
+  // Create an optional
+  std::optional<TestOptionalStruct*> opt(new TestOptionalStruct(42));
+
+  // Serialize it
+  std::stringstream ss;
+  boost::archive::text_oarchive oa(ss);
+  oa << opt;
+
+  // Deserialize it
+  std::optional<TestOptionalStruct*> opt2;
+  boost::archive::text_iarchive ia(ss);
+  ia >> opt2;
+
+  // Check that it worked
+  EXPECT(opt2.has_value());
+  EXPECT(**opt2 == TestOptionalStruct(42));
+}
+
 int main() {
   TestResult tr;
   return TestRegistry::runAllTests(tr);