Initial public release of nearby library

Signed-off-by: Alexey Polyudov <apolyudov@google.com>
Change-Id: I85d490e448375aa4eb7b09680757c02fff1420b4

cpp/platform/logging.h

@@ -0,0 +1,43 @@
+// Copyright 2020 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef PLATFORM_LOGGING_H_
+#define PLATFORM_LOGGING_H_
+
+#include "absl/base/internal/raw_logging.h"
+
+namespace location {
+namespace nearby {
+
+// This uses an explicit printf-format and arguments list, and supports the
+// following severities:
+//
+//    - INFO
+//    - WARNING
+//    - ERROR
+//    - FATAL
+//
+// To make it easy to filer while debugging, it prepends "[NEARBY] " to all its
+// logged messages.
+//
+// Sample usage:
+//
+//      NEARBY_LOG(INFO, "%d is an int and %s is a std::string", i, s.c_str());
+#define NEARBY_LOG(severity, ...) \
+  ABSL_RAW_LOG(severity, "[NEARBY] " __VA_ARGS__)
+
+}  // namespace nearby
+}  // namespace location
+
+#endif  // PLATFORM_LOGGING_H_