[stdex] Introduce Queue.h (#2484)

This commit introduces Queue.h which will hold various utilities for
std::queue<T>.

The current implementation includes only one helper: 'take'.

Signed-off-by: Jonghyun Park <jh1302.park@samsung.com>

diff --git a/contrib/stdex/include/stdex/Queue.h b/contrib/stdex/include/stdex/Queue.h
new file mode 100644 (file)
index 0000000..c72297b
--- /dev/null
+++ b/contrib/stdex/include/stdex/Queue.h
@@ -0,0 +1,38 @@
+/*
+ * Copyright (c) 2018 Samsung Electronics Co., Ltd. All Rights Reserved
+ *
+ * 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
+ *
+ *    http://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 __STDEX_QUEUE_H__
+#define __STDEX_QUEUE_H__
+
+#include <queue>
+
+namespace stdex
+{
+
+/**
+ * @brief Take the front (= first) element from the queue
+ * @note The queue SHOULD have at least one element
+ */
+template <typename T> T take(std::queue<T> &q)
+{
+  auto res = q.front();
+  q.pop();
+  return res;
+}
+
+} // namespace stdex
+
+#endif // __STDEX_QUEUE_H__

diff --git a/contrib/stdex/src/Queue.test.cpp b/contrib/stdex/src/Queue.test.cpp
new file mode 100644 (file)
index 0000000..d76cd3e
--- /dev/null
+++ b/contrib/stdex/src/Queue.test.cpp
@@ -0,0 +1,32 @@
+/*
+ * Copyright (c) 2018 Samsung Electronics Co., Ltd. All Rights Reserved
+ *
+ * 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
+ *
+ *    http://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.
+ */
+
+#include "stdex/Queue.h"
+
+#include <gtest/gtest.h>
+
+TEST(QueueTest, take)
+{
+  std::queue<int> q;
+
+  q.emplace(3);
+  q.emplace(4);
+  q.emplace(5);
+
+  ASSERT_EQ(stdex::take(q), 3);
+  ASSERT_EQ(stdex::take(q), 4);
+  ASSERT_EQ(stdex::take(q), 5);
+}