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// Copyright 2005, Google Inc.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// A sample program demonstrating using Google C++ testing framework.
//
// Author: wan@google.com (Zhanyong Wan)
#ifndef GTEST_SAMPLES_SAMPLE3_INL_H_
#define GTEST_SAMPLES_SAMPLE3_INL_H_
#include <stddef.h>
// Queue is a simple queue implemented as a singled-linked list.
//
// The element type must support copy constructor.
template <typename E> // E is the element type
class Queue;
// QueueNode is a node in a Queue, which consists of an element of
// type E and a pointer to the next node.
template <typename E> // E is the element type
class QueueNode { friend class Queue<E>;
public: // Gets the element in this node.
const E& element() const { return element_; }
// Gets the next node in the queue.
QueueNode* next() { return next_; } const QueueNode* next() const { return next_; }
private: // Creates a node with a given element value. The next pointer is
// set to NULL.
QueueNode(const E& an_element) : element_(an_element), next_(NULL) {}
// We disable the default assignment operator and copy c'tor.
const QueueNode& operator = (const QueueNode&); QueueNode(const QueueNode&);
E element_; QueueNode* next_; };
template <typename E> // E is the element type.
class Queue { public:
// Creates an empty queue.
Queue() : head_(NULL), last_(NULL), size_(0) {}
// D'tor. Clears the queue.
~Queue() { Clear(); }
// Clears the queue.
void Clear() { if (size_ > 0) { // 1. Deletes every node.
QueueNode<E>* node = head_; QueueNode<E>* next = node->next(); for (; ;) { delete node; node = next; if (node == NULL) break; next = node->next(); }
// 2. Resets the member variables.
head_ = last_ = NULL; size_ = 0; } }
// Gets the number of elements.
size_t Size() const { return size_; }
// Gets the first element of the queue, or NULL if the queue is empty.
QueueNode<E>* Head() { return head_; } const QueueNode<E>* Head() const { return head_; }
// Gets the last element of the queue, or NULL if the queue is empty.
QueueNode<E>* Last() { return last_; } const QueueNode<E>* Last() const { return last_; }
// Adds an element to the end of the queue. A copy of the element is
// created using the copy constructor, and then stored in the queue.
// Changes made to the element in the queue doesn't affect the source
// object, and vice versa.
void Enqueue(const E& element) { QueueNode<E>* new_node = new QueueNode<E>(element);
if (size_ == 0) { head_ = last_ = new_node; size_ = 1; } else { last_->next_ = new_node; last_ = new_node; size_++; } }
// Removes the head of the queue and returns it. Returns NULL if
// the queue is empty.
E* Dequeue() { if (size_ == 0) { return NULL; }
const QueueNode<E>* const old_head = head_; head_ = head_->next_; size_--; if (size_ == 0) { last_ = NULL; }
E* element = new E(old_head->element()); delete old_head;
return element; }
// Applies a function/functor on each element of the queue, and
// returns the result in a new queue. The original queue is not
// affected.
template <typename F> Queue* Map(F function) const { Queue* new_queue = new Queue(); for (const QueueNode<E>* node = head_; node != NULL; node = node->next_) { new_queue->Enqueue(function(node->element())); }
return new_queue; }
private: QueueNode<E>* head_; // The first node of the queue.
QueueNode<E>* last_; // The last node of the queue.
size_t size_; // The number of elements in the queue.
// We disallow copying a queue.
Queue(const Queue&); const Queue& operator = (const Queue&); };
#endif // GTEST_SAMPLES_SAMPLE3_INL_H_
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