Roll forward to cl/338482889

Signed-off-by: Alexey Polyudov <apolyudov@google.com>
Change-Id: Ic2bdb234e89f3c5860d1b483dd4bce689f13d057

cpp/core/status.h

@@ -19,24 +19,41 @@ namespace location {
 namespace nearby {
 namespace connections {
 
+// Protocol operation result: kSuccess, if operation was successful;
+// descriptive error code otherwise.
 struct Status {
+  // Status is a struct, so it is possible to pass some context about failure,
+  // by adding extra fields to it when necessary, and not change any of the
+  // method signatures.
   enum Value {
-    SUCCESS,
-    ERROR,
-    OUT_OF_ORDER_API_CALL,
-    ALREADY_HAVE_ACTIVE_STRATEGY,
-    ALREADY_ADVERTISING,
-    ALREADY_DISCOVERING,
-    ENDPOINT_IO_ERROR,
-    ENDPOINT_UNKNOWN,
-    CONNECTION_REJECTED,
-    ALREADY_CONNECTED_TO_ENDPOINT,
-    NOT_CONNECTED_TO_ENDPOINT,
-    BLUETOOTH_ERROR,
-    PAYLOAD_UNKNOWN,
+    kSuccess,
+    kError,
+    kOutOfOrderApiCall,
+    kAlreadyHaveActiveStrategy,
+    kAlreadyAdvertising,
+    kAlreadyDiscovering,
+    kEndpointIoError,
+    kEndpointUnknown,
+    kConnectionRejected,
+    kAlreadyConnectedToEndpoint,
+    kNotConnectedToEndpoint,
+    kBluetoothError,
+    kBleError,
+    kWifiLanError,
+    kPayloadUnknown,
   };
+  Value value {kError};
+  bool Ok() const { return value == kSuccess; }
 };
 
+inline bool operator==(const Status& a, const Status& b) {
+  return a.value == b.value;
+}
+
+inline bool operator!=(const Status& a, const Status& b) {
+  return !(a == b);
+}
+
 }  // namespace connections
 }  // namespace nearby
 }  // namespace location