added reverser iterator and corresponding tests

Author: vinitjames

circular_buffer.h

@@ -109,6 +109,11 @@ class CircularBuffer {
 	const_iterator end() const;
 	const_iterator cbegin() const noexcept;
 	const_iterator cend() const noexcept;
+	iterator rbegin() noexcept;
+	const_iterator rbegin() const noexcept;
+	iterator rend() noexcept;
+	const_iterator rend() const noexcept;
+	
 
 private:
 	void _increment_bufferstate();
@@ -153,7 +158,7 @@ class CircularBuffer {
 
 		reference operator*(){
 			if(_reverse)
-				return (*_ptrToBuffer)[(_ptrToBuffer->size() - _index)];
+				return (*_ptrToBuffer)[(_ptrToBuffer->size() - _index - 1)];
 			return (*_ptrToBuffer)[_index];
 		}
 
@@ -484,4 +489,53 @@ typename CircularBuffer<T>::const_iterator CircularBuffer<T>::cend() const noexc
 	iter._reverse = false;
 	return iter;
 }
+
+template<typename T>
+inline 
+typename CircularBuffer<T>::iterator CircularBuffer<T>::rbegin() noexcept{
+	std::lock_guard<std::mutex> _lck(_mtx);
+	iterator iter;
+	iter._ptrToBuffer = this;
+	iter._offset = _tail;
+	iter._index = 0;
+	iter._reverse = true;
+	return iter;
+}
+
+template<typename T>
+inline 
+typename CircularBuffer<T>::const_iterator CircularBuffer<T>::rbegin() const noexcept{
+	std::lock_guard<std::mutex> _lck(_mtx);
+	const_iterator iter;
+	iter._ptrToBuffer = this;
+	iter._offset = _tail;
+	iter._index = 0;
+	iter._reverse = true;
+	return iter;
+}
+
+template<typename T>
+inline 
+typename CircularBuffer<T>::iterator CircularBuffer<T>::rend()  noexcept{
+	std::lock_guard<std::mutex> _lck(_mtx);
+	iterator iter;
+	iter._ptrToBuffer = this;
+	iter._offset = _tail;
+	iter._index = _size;
+	iter._reverse = true;
+	return iter;
+}
+
+template<typename T>
+inline 
+typename CircularBuffer<T>::const_iterator CircularBuffer<T>::rend() const noexcept{
+	std::lock_guard<std::mutex> _lck(_mtx);
+	const_iterator iter;
+	iter._ptrToBuffer = this;
+	iter._offset = _tail;
+	iter._index = _size;
+	iter._reverse = true;
+	return iter;
+}
+
 #endif /* CIRCULAR_BUFFER_H */

tests/member_func_test.cpp

@@ -316,6 +316,38 @@ TEST_F(CircularBufferTest, BeginIteratorTest){
 	}
 }
 
+TEST_F(CircularBufferTest, RbeginIteratorTest){	
+	//create full buffer
+	for(int i=0; i<TEST_BUFFER_SIZE; i++)
+		test_buff.push_back("string" + std::to_string(i));
+    //test first element with iterator
+	CircularBuffer<std::string>::iterator it = test_buff.rbegin();
+	//access with rbegin iterator	
+	for(int i=TEST_BUFFER_SIZE-1; i>=0; i--)
+		EXPECT_EQ(*(it++), "string" + std::to_string(i));
+
+	//access with const begin iterator
+	CircularBuffer<std::string>::const_iterator const_it = test_buff.rbegin(); 
+	for(int i=TEST_BUFFER_SIZE - 1; i>=0;  i--)
+		EXPECT_EQ(*(const_it++), "string" + std::to_string(i));
+	//test out of bounds
+	try {
+		*it = "test_string";
+		FAIL() << "Expected std::out_of_range error";
+	}
+	catch(const std::out_of_range& err){
+		EXPECT_EQ(err.what(), std::string("Index is out of Range of buffer size"));
+	}
+
+	try {
+		std::string out_of_bound = *(const_it);
+		FAIL() << "Expected std::out_of_range error";
+	}
+	catch(const std::out_of_range& err){
+		EXPECT_EQ(err.what(), std::string("Index is out of Range of buffer size"));
+		}
+}
+
 TEST_F(CircularBufferTest, CbeginIteratorTest){	
 	//create full buffer
 	for(int i=0; i<TEST_BUFFER_SIZE; i++)
@@ -334,7 +366,8 @@ TEST_F(CircularBufferTest, CbeginIteratorTest){
 	catch(const std::out_of_range& err){
 		EXPECT_EQ(err.what(), std::string("Index is out of Range of buffer size"));
 	}
-	}
+}
+
 
 TEST_F(CircularBufferTest, EndIteratorTest){	
 	//create full buffer
@@ -369,6 +402,39 @@ TEST_F(CircularBufferTest, EndIteratorTest){
 	}
 }
 
+TEST_F(CircularBufferTest, RendIteratorTest){	
+	//create full buffer
+	for(int i=0; i<TEST_BUFFER_SIZE; i++)
+		test_buff.push_back("string" + std::to_string(i));
+    //test first element with iterator
+	CircularBuffer<std::string>::iterator it = test_buff.rend() - 1;
+	//access with rbegin iterator	
+	for(int i=0; i<TEST_BUFFER_SIZE; i++)
+		EXPECT_EQ(*(it--), "string" + std::to_string(i));
+
+	//access with const begin iterator
+	CircularBuffer<std::string>::const_iterator const_it = test_buff.rend() - 1; 
+	for(int i=0; i<TEST_BUFFER_SIZE; i++)
+		EXPECT_EQ(*(const_it--), "string" + std::to_string(i));
+	//test out of bounds
+	try {
+		*it = "test_string";
+		FAIL() << "Expected std::out_of_range error";
+	}
+	catch(const std::out_of_range& err){
+		EXPECT_EQ(err.what(), std::string("Index is out of Range of buffer size"));
+	}
+
+	try {
+		std::string out_of_bound = *(const_it);
+		FAIL() << "Expected std::out_of_range error";
+	}
+	catch(const std::out_of_range& err){
+		EXPECT_EQ(err.what(), std::string("Index is out of Range of buffer size"));
+		}
+}
+
+
 TEST_F(CircularBufferTest, CendIteratorTest){	
 	//create full buffer
 	for(int i=0; i<TEST_BUFFER_SIZE; i++)