fixed bug with constant iterator

Author: vinitjames

circular_buffer.h

@@ -108,6 +108,8 @@ class CircularBuffer {
 	const_iterator begin() const;
 	iterator end();
 	const_iterator end() const;
+	const_iterator cbegin() const noexcept;
+	const_iterator cend() const noexcept;
 
 private:
 	void _increment_bufferstate();
@@ -127,14 +129,15 @@ class CircularBuffer {
 		typedef std::random_access_iterator_tag iterator_type;
 		typedef typename std::conditional<isConst, const value_type&, value_type&>::type reference;
 		typedef typename std::conditional<isConst, const value_type*, value_type*>::type pointer;
-		typedef CircularBuffer*  cbuf_pointer;
+		typedef typename std::conditional<isConst, const CircularBuffer<value_type>*,
+										  CircularBuffer<value_type>*>::type cbuf_pointer;
 
 		cbuf_pointer _ptrToBuffer;
 		size_type _offset;
 		size_type _index;
 		bool _reverse;
 
-		bool _comparable(const BufferIterator& other){
+		bool _comparable(const BufferIterator<isConst>& other) const{
 			return (_ptrToBuffer == other._ptrToBuffer)&&(_reverse == other._reverse);
 		}
 
@@ -208,37 +211,37 @@ class CircularBuffer {
 			return *this;
 		}
 
-		bool operator==(const BufferIterator& other){
+		bool operator==(const BufferIterator& other) const{
 			if (!_comparable(other))
 				return false;
 			return ((_index == other._index)&&(_offset == other._offset));
 		}
 
-		bool operator!=(const BufferIterator& other){
+		bool operator!=(const BufferIterator& other) const{
 			if (!_comparable(other))
 				return true;
 			return ((_index != other._index)||(_offset != other._offset));
 		}
 
-		bool operator<(const BufferIterator& other){
+		bool operator<(const BufferIterator& other) const {
 			if (!_comparable(other))
 				return false;
 			return ((_index + _offset)<(other._index+other._offset));
 		}
 
-		bool operator>(const BufferIterator& other){
+		bool operator>(const BufferIterator& other) const{
 			if (!_comparable(other))
 				return false;
 			return ((_index + _offset)>(other._index+other._offset));
 		}
 
-		bool operator<=(const BufferIterator& other){
+		bool operator<=(const BufferIterator& other) const {
 			if (!_comparable(other))
 				return false;
 			return ((_index + _offset)<=(other._index+other._offset));
 		}
 
-		bool operator>=(const BufferIterator& other){
+		bool operator>=(const BufferIterator& other) const {
 			if (!_comparable(other))
 				return false;
 			return ((_index + _offset)>=(other._index+other._offset));
@@ -452,4 +455,27 @@ typename CircularBuffer<T>::const_iterator CircularBuffer<T>::end() const{
 	return iter;
 }
 
+template<typename T>
+inline 
+typename CircularBuffer<T>::const_iterator CircularBuffer<T>::cbegin() const noexcept{
+	std::lock_guard<std::mutex> _lck(_mtx);
+	const_iterator iter;
+	iter._ptrToBuffer = this;
+	iter._offset = _tail;
+	iter._index = 0;
+	iter._reverse = false;
+	return iter;
+}
+
+template<typename T>
+inline 
+typename CircularBuffer<T>::const_iterator CircularBuffer<T>::cend() const noexcept{
+	std::lock_guard<std::mutex> _lck(_mtx);
+	const_iterator iter;
+	iter._ptrToBuffer = this;
+	iter._offset = _tail;
+	iter._index = _size;
+	iter._reverse = false;
+	return iter;
+}
 #endif /* CIRCULAR_BUFFER_H */

tests/string_buffer.cpp

@@ -316,6 +316,25 @@ TEST_F(CircularBufferTest, BeginIteratorTest){
 	}
 }
 
+TEST_F(CircularBufferTest, CbeginIteratorTest){	
+	//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>::const_iterator const_it = test_buff.cbegin();
+	EXPECT_EQ(*const_it, "string0" );
+	//access with begin iterator	
+	for(int i=0; i<TEST_BUFFER_SIZE; i++)
+		EXPECT_EQ(*(const_it++), "string" + std::to_string(i));
+	
+	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, EndIteratorTest){	
 	//create full buffer
@@ -348,9 +367,28 @@ TEST_F(CircularBufferTest, EndIteratorTest){
 	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++)
+		test_buff.push_back("string" + std::to_string(i));
+
+	CircularBuffer<std::string>::const_iterator const_it = test_buff.cend(); 
+	//access with end iterator	
+	for(int i = TEST_BUFFER_SIZE-1; i>=0; i--)
+		EXPECT_EQ(*(--const_it), "string" + std::to_string(i));
+
+	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, IteratorBasedLoopTest){	
 	//create full buffer
 	for(int i=0; i<TEST_BUFFER_SIZE; i++)
@@ -368,6 +406,7 @@ TEST_F(CircularBufferTest, IteratorBasedLoopTest){
 		EXPECT_EQ(*it, "string" + std::to_string(i++));
 	//test size with increment variable
 	EXPECT_EQ(i, TEST_BUFFER_SIZE/2);
+	
 
 }
 
@@ -412,3 +451,4 @@ TEST_F(CircularBufferTest, RangeBasedLoopTest){
 
 
 
+