diff --git a/cpp-client/.clang-format b/cpp-client/.clang-format
new file mode 100644
index 00000000000..f98f35d4ea8
--- /dev/null
+++ b/cpp-client/.clang-format
@@ -0,0 +1,5 @@
+BasedOnStyle: Google
+IndentWidth: 2
+
+---
+Language: Cpp
diff --git a/cpp-client/deephaven/dhcore/include/private/deephaven/dhcore/immerutil/immer_column_source.h b/cpp-client/deephaven/dhcore/include/private/deephaven/dhcore/immerutil/immer_column_source.h
index 4f37064b728..30ad0b42dc0 100644
--- a/cpp-client/deephaven/dhcore/include/private/deephaven/dhcore/immerutil/immer_column_source.h
+++ b/cpp-client/deephaven/dhcore/include/private/deephaven/dhcore/immerutil/immer_column_source.h
@@ -61,6 +61,9 @@ struct ImmerColumnSourceImpls {
           if (destNullp != nullptr) {
             *destNullp++ = value == deephaven::dhcore::DeephavenTraits<T>::NULL_VALUE;
           }
+        } else {
+          // avoid clang complaining about unused variables
+          (void)destNullp;
         }
       }
     };
@@ -83,6 +86,11 @@ struct ImmerColumnSourceImpls {
           auto nullsEndp = srcNullFlags->begin() + srcEnd;
           immer::for_each_chunk(nullsBeginp, nullsEndp, copyNullsInner);
         }
+      } else {
+        // avoid clang complaining about unused variables.
+        (void)srcNullFlags;
+        (void)destNullp;
+        (void)copyNullsInner;
       }
     };
     rows.forEachInterval(copyOuter);
diff --git a/cpp-client/deephaven/dhcore/include/private/deephaven/dhcore/ticking/index_decoder.h b/cpp-client/deephaven/dhcore/include/private/deephaven/dhcore/ticking/index_decoder.h
index df2b76c7cc6..e06de361717 100644
--- a/cpp-client/deephaven/dhcore/include/private/deephaven/dhcore/ticking/index_decoder.h
+++ b/cpp-client/deephaven/dhcore/include/private/deephaven/dhcore/ticking/index_decoder.h
@@ -12,8 +12,8 @@ class DataInput {
 public:
   explicit DataInput(const flatbuffers::Vector<int8_t> &vec) : DataInput(vec.data(), vec.size()) {}
 
-  DataInput(const void *start, size_t size) : data_(static_cast<const char *>(start)),
-      size_(size) {}
+  DataInput(const void *start, size_t size) : data_(static_cast<const char *>(start))
+    {}
 
   int64_t readValue(int command);
 
@@ -24,7 +24,6 @@ class DataInput {
 
 private:
   const char *data_ = nullptr;
-  size_t size_ = 0;
 };
 
 struct IndexDecoder {
diff --git a/cpp-client/deephaven/dhcore/include/public/deephaven/dhcore/types.h b/cpp-client/deephaven/dhcore/include/public/deephaven/dhcore/types.h
index 58c786bd591..8d42206fbe9 100644
--- a/cpp-client/deephaven/dhcore/include/public/deephaven/dhcore/types.h
+++ b/cpp-client/deephaven/dhcore/include/public/deephaven/dhcore/types.h
@@ -117,8 +117,7 @@ class DeephavenConstants {
   /**
    * The minimum finite value for the Deephaven float type.
    */
-  static constexpr const float MIN_FINITE_FLOAT = std::nextafter(-std::numeric_limits<float>::max(),
-      0.0f);
+  static /* constexpr clang dislikes */ const float MIN_FINITE_FLOAT;
   /**
    * The maximum finite value for the Deephaven float type.
    */
@@ -155,8 +154,7 @@ class DeephavenConstants {
   /**
    * The minimum finite value for the Deephaven double type.
    */
-  static constexpr const double MIN_FINITE_DOUBLE = std::nextafter(
-      -std::numeric_limits<double>::max(), 0.0f);
+  static /* constexpr clang dislikes */ const double MIN_FINITE_DOUBLE;
   /**
    * The maximum finite value for the Deephaven double type.
    */
diff --git a/cpp-client/deephaven/dhcore/src/ticking/space_mapper.cc b/cpp-client/deephaven/dhcore/src/ticking/space_mapper.cc
index 1ff916e6eaf..4daa3182235 100644
--- a/cpp-client/deephaven/dhcore/src/ticking/space_mapper.cc
+++ b/cpp-client/deephaven/dhcore/src/ticking/space_mapper.cc
@@ -28,10 +28,6 @@ struct SimpleRangeIterator {
     return *this;
   }
 
-  friend bool operator!=(const SimpleRangeIterator &lhs, const SimpleRangeIterator &rhs) {
-    return lhs.value_ != rhs.value_;
-  }
-
   uint64_t value_;
 };
 }
diff --git a/cpp-client/deephaven/dhcore/src/types.cc b/cpp-client/deephaven/dhcore/src/types.cc
index 6129dbb5e1d..61d3b80cf33 100644
--- a/cpp-client/deephaven/dhcore/src/types.cc
+++ b/cpp-client/deephaven/dhcore/src/types.cc
@@ -3,6 +3,8 @@
  */
 #include "deephaven/dhcore/types.h"
 
+#include <limits>
+
 namespace deephaven::dhcore {
 const char16_t DeephavenConstants::NULL_CHAR;
 
@@ -12,7 +14,8 @@ const float DeephavenConstants::NEG_INFINITY_FLOAT;
 const float DeephavenConstants::POS_INFINITY_FLOAT;
 const float DeephavenConstants::MIN_FLOAT;
 const float DeephavenConstants::MAX_FLOAT;
-const float DeephavenConstants::MIN_FINITE_FLOAT;
+const float DeephavenConstants::MIN_FINITE_FLOAT =
+  std::nextafter(-std::numeric_limits<float>::max(), 0.0f);
 const float DeephavenConstants::MAX_FINITE_FLOAT;
 const float DeephavenConstants::MIN_POS_FLOAT;
 
@@ -22,7 +25,8 @@ const double DeephavenConstants::NEG_INFINITY_DOUBLE;
 const double DeephavenConstants::POS_INFINITY_DOUBLE;
 const double DeephavenConstants::MIN_DOUBLE;
 const double DeephavenConstants::MAX_DOUBLE;
-const double DeephavenConstants::MIN_FINITE_DOUBLE;
+const double DeephavenConstants::MIN_FINITE_DOUBLE =
+  std::nextafter(-std::numeric_limits<double>::max(), 0.0);
 const double DeephavenConstants::MAX_FINITE_DOUBLE;
 const double DeephavenConstants::MIN_POS_DOUBLE;