Add ApiTest.cpp

RootSet.cpp

@@ -188,14 +188,14 @@ int main() {
 
   RootSet rs;
   std::latch ready{1 + kNumReaders};
-  std::atomic<int> version;
-  std::vector<std::atomic<int>> doneVersions(kNumReaders);
+  std::atomic<uint32_t> version;
+  std::vector<std::atomic<uint32_t>> doneVersions(kNumReaders);
   std::thread writer([&]() {
     ready.arrive_and_wait();
     for (int i = 0; i < kNumVersions; ++i) {
       rs.add(i / 10, i);
       version.store(i);
-      int min = std::numeric_limits<int>::max();
+      uint32_t min = -1;
       for (auto &v : doneVersions) {
         min = std::min(min, v.load());
       }