Add bit field utility functions

test/utils/CMakeLists.txt

@@ -16,7 +16,7 @@ endif()
 include(Catch)
 
 add_executable(unittests_edm4hep
-  test_kinematics.cpp test_vector_utils.cpp test_covmatrix_utils.cpp test_PIDHandler.cpp)
+  test_kinematics.cpp test_vector_utils.cpp test_covmatrix_utils.cpp test_PIDHandler.cpp test_bit_utils.cpp)
 
 target_link_libraries(unittests_edm4hep edm4hep EDM4HEP::utils Catch2::Catch2 Catch2::Catch2WithMain)
 

test/utils/test_bit_utils.cpp

@@ -0,0 +1,25 @@
+#include "edm4hep/utils/bit_utils.h"
+
+#include <catch2/catch_template_test_macros.hpp>
+#include <catch2/catch_test_macros.hpp>
+
+#include <cstdint>
+#include <tuple>
+
+// The integet types that we us as type fields in EDM4hep
+using BitFieldTypes = std::tuple<int32_t, uint32_t, int64_t, int16_t, uint64_t>;
+
+TEMPLATE_LIST_TEST_CASE("Bitfield utils set and get", "[bit_utils]", BitFieldTypes) {
+  using namespace edm4hep;
+  auto bitField = TestType{};
+
+  for (auto i = 0u; i < sizeof(TestType) * 8; ++i) {
+    REQUIRE_FALSE(utils::checkBit(bitField, i));
+  }
+
+  bitField = utils::setBit(bitField, 3, true);
+  REQUIRE(utils::checkBit(bitField, 3));
+
+  bitField = utils::setBit(bitField, 3, false);
+  REQUIRE_FALSE(utils::checkBit(bitField, 3));
+}

utils/include/edm4hep/utils/bit_utils.h

@@ -0,0 +1,16 @@
+#ifndef EDM4HEP_UTILS_BIT_UTILS_HH
+#define EDM4HEP_UTILS_BIT_UTILS_HH
+
+namespace edm4hep::utils {
+template <typename T>
+constexpr T setBit(T bits, int bitNum, bool value) {
+  return (bits & ~(1 << bitNum)) | (value << bitNum);
+}
+
+template <typename T>
+constexpr bool checkBit(T bits, int bitNum) {
+  return bits & (0x1 << bitNum);
+}
+} // namespace edm4hep::utils
+
+#endif // EDM4HEP_UTILS_BIT_UTILS_HH