Change client :method selection based on idempotency
diff --git a/include/grpc/impl/codegen/grpc_types.h b/include/grpc/impl/codegen/grpc_types.h
index 2c39f4b..993fc97 100644
--- a/include/grpc/impl/codegen/grpc_types.h
+++ b/include/grpc/impl/codegen/grpc_types.h
@@ -199,6 +199,12 @@
/** Mask of all valid flags. */
#define GRPC_WRITE_USED_MASK (GRPC_WRITE_BUFFER_HINT | GRPC_WRITE_NO_COMPRESS)
+/* Initial metadata flags */
+/** Signal that the call is idempotent */
+#define GRPC_INITIAL_METADATA_IDEMPOTENT_REQUEST (0x00000010u)
+/** Mask of all valid flags */
+#define GRPC_INITIAL_METADATA_USED_MASK GRPC_INITIAL_METADATA_IDEMPOTENT_REQUEST
+
/** A single metadata element */
typedef struct grpc_metadata {
const char *key;