Refactor Input/Output file to use const char* instead of standard string, and to use parent_folder and file_name for input and output files. This also incorporates the move from nearby_connections to nearby.

PiperOrigin-RevId: 415587802

cpp/platform/base/BUILD

@@ -29,6 +29,7 @@ cc_library(
         "bluetooth_utils.h",
         "byte_array.h",
         "callable.h",
+        "core_config.h",
         "exception.h",
         "feature_flags.h",
         "input_stream.h",

cpp/platform/base/core_config.h

@@ -0,0 +1,38 @@
+// 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 CORE_CONFIG_H_
+#define CORE_CONFIG_H_
+
+namespace location {
+namespace nearby {
+namespace connections {
+
+#ifdef _WIN32  // These storage class specifiers only matter to win32 dll
+               // builds.
+#ifdef CORE_ADAPTER_DLL
+#define DLL_API \
+  __declspec(dllexport)  // If we're building the core, we're exporting.
+#else                    // !CORE_ADAPTER_DLL
+#define DLL_API \
+  __declspec(dllimport)  // If we're not building the core, we're importing.
+#endif                   // CORE_ADAPTER_DLL
+#else                    // !_WIN32
+#define DLL_API  // We're not building a win32 dll, leave the source unchanged.
+#endif           // _WIN32
+
+}  // namespace connections
+}  // namespace nearby
+}  // namespace location
+
+#endif  // CORE_CONFIG_H_