Testing out static constexpr absl::string_view in header

include/grpcpp/ext/otel_plugin.h

@@ -39,6 +39,7 @@ class OpenTelemetryPluginBuilderImpl;
 namespace experimental {
 // Metrics
 absl::string_view OpenTelemetryClientAttemptStartedInstrumentName();
+absl::string_view OpenTelemetryClientAttemptStartedInstrumentName();
 absl::string_view OpenTelemetryClientAttemptDurationInstrumentName();
 absl::string_view
 OpenTelemetryClientAttemptSentTotalCompressedMessageSizeInstrumentName();
@@ -66,6 +67,9 @@ OpenTelemetryServerCallRcvdTotalCompressedMessageSizeInstrumentName();
 /// grpc.server.call.rcvd_total_compressed_message_size
 class OpenTelemetryPluginBuilder {
  public:
+  static constexpr absl::string_view kClientAttemptStartedInstrumentName =
+      "grpc.client.attempt.started";
+
   OpenTelemetryPluginBuilder();
   /// If `SetMeterProvider()` is not called, no metrics are collected.
   OpenTelemetryPluginBuilder& SetMeterProvider(

src/cpp/ext/otel/otel_plugin.cc

@@ -266,6 +266,10 @@ void OpenTelemetryPluginBuilderImpl::BuildAndRegisterGlobal() {
 }  // namespace internal
 
 namespace experimental {
+
+constexpr absl::string_view
+    OpenTelemetryPluginBuilder::kClientAttemptStartedInstrumentName;
+
 absl::string_view OpenTelemetryClientAttemptStartedInstrumentName() {
   return "grpc.client.attempt.started";
 }

test/cpp/ext/csm/metadata_exchange_test.cc

@@ -206,8 +206,8 @@ class MetadataExchangeTest
 
 // Verify that grpc.client.attempt.started does not get service mesh attributes
 TEST_P(MetadataExchangeTest, ClientAttemptStarted) {
-  Init(/*metric_names=*/{
-      grpc::experimental::OpenTelemetryClientAttemptStartedInstrumentName()});
+  Init(/*metric_names=*/{grpc::experimental::OpenTelemetryPluginBuilder::
+                             kClientAttemptStartedInstrumentName});
   SendRPC();
   const char* kMetricName = "grpc.client.attempt.started";
   auto data = ReadCurrentMetricsData(