Add rtc::Optional::reset

webrtc/base/optional_unittest.cc

 /*
  *  Copyright 2015 The WebRTC Project Authors. All rights reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 351 matching lines @@
   }
   EXPECT_EQ(
       V("0:17. explicit constructor", "1:17. move constructor (from 0:17)",
         "0:17. destructor", "2:42. explicit constructor", "---",
         "3:42. move constructor (from 2:42)",
         "1:42. operator= move (from 3:42)", "3:42. destructor", "---",
         "2:42. destructor", "1:42. destructor"),
       *log);
 }
 
+TEST(OptionalTest, TestResetEmpty) {
+  auto log = Logger::Setup();
+  {
+    Optional<Logger> x;
+    x.reset();
+  }
+  EXPECT_EQ(V(), *log);
+}
+
+TEST(OptionalTest, TestResetFull) {
+  auto log = Logger::Setup();
+  {
+    Optional<Logger> x(Logger(17));
+    log->push_back("---");
+    x.reset();
+    log->push_back("---");
+  }
+  EXPECT_EQ(
+      V("0:17. explicit constructor", "1:17. move constructor (from 0:17)",
+        "0:17. destructor", "---", "1:17. destructor", "---"),
+      *log);
+}
+
 TEST(OptionalTest, TestDereference) {
   auto log = Logger::Setup();
   {
     Optional<Logger> x(Logger(42));
     const auto& y = x;
     log->push_back("---");
     x->Foo();
     y->Foo();
     std::move(x)->Foo();
     std::move(y)->Foo();
@@ skipping 81 matching lines @@
               "2:17. copy constructor (from 0:17)",
               "3:42. copy constructor (from 1:42)",
               "4:17. copy constructor (from 0:17)", "---", "swap 2:42, 3:17",
               "5:17. move constructor (from 4:17)", "4:17. destructor", "---",
               "5:17. destructor", "3:17. destructor", "2:42. destructor",
               "1:42. destructor", "0:17. destructor"),
             *log);
 }
 
 }  // namespace rtc