added at operator for circular with size checking

Author: VinitJamesVW

circular_buffer.h

@@ -40,8 +40,11 @@ class CircularBuffer {
 	size_type capacity() const ;
 	size_type size() const;
 	size_type buffer_size() const {return sizeof(T)*_max_size;};
+	
 	const_reference operator[](size_type index) const;
 	reference operator[](size_type index);
+	const_reference at(size_type index) const;
+	reference at(size_type index);
 
 	iterator begin();
 	const_iterator begin() const;
@@ -287,16 +290,16 @@ void CircularBuffer<T>::pop_front(){
 template<typename T>
 inline 
 void CircularBuffer<T>::_decrement_bufferstate(){
-	//_full = false;
 	--_size;
 	_tail = (_tail + 1)%_max_size;
 }
 
 template<typename T>
 inline 
 typename CircularBuffer<T>::reference CircularBuffer<T>::operator[](size_t index) {
-	if((index<0)||(index>_max_size))
-		throw std::out_of_range("Index is out of Range of buffer size");
+	std::lock_guard<std::mutex> _lck(_mtx);
+	if((index<0)||(index>=_max_size))
+		throw std::out_of_range("Index is out of Range of buffer capacity");
 	index += _tail;
 	index %= _max_size;
 	return _buff[index];
@@ -305,7 +308,29 @@ typename CircularBuffer<T>::reference CircularBuffer<T>::operator[](size_t index
 template<typename T>
 inline 
 typename CircularBuffer<T>::const_reference CircularBuffer<T>::operator[](size_t index) const {
-	if((index<0)||(index>_max_size))
+	std::lock_guard<std::mutex> _lck(_mtx);
+	if((index<0)||(index>=_max_size))
+		throw std::out_of_range("Index is out of Range of buffer capacity");
+	index += _tail;
+	index %= _max_size;
+	return _buff[index];
+}
+
+template<typename T>
+inline 
+typename CircularBuffer<T>::reference CircularBuffer<T>::at(size_t index) {
+	std::lock_guard<std::mutex> _lck(_mtx);
+	if((index<0)||(index>=_size))
+		throw std::out_of_range("Index is out of Range of buffer size");
+	index += _tail;
+	index %= _max_size;
+	return _buff[index];
+}
+
+template<typename T>
+inline 
+typename CircularBuffer<T>::const_reference CircularBuffer<T>::at(size_t index) const {
+	if((index<0)||(index>=_size))
 		throw std::out_of_range("Index is out of Range of buffer size");
 	index += _tail;
 	index %= _max_size;

samples/sample_circularbuffer.cpp

@@ -31,6 +31,10 @@ struct test_struct{
 		std::cout<<"destructing test_struct"<<--count<<"\n";
 		free(bytes);
 	}
+
+	friend std::ostream& operator<<(std::ostream& os, const test_struct& ts){
+		return os<<"test\n";
+	}
 
 
 };
@@ -91,13 +95,24 @@ int main(int argc, char *argv[])
 	std::cout<<"Checking deference -- operator "<<*(--it)<<"\n";
 
 	CircularBuffer<test_struct> test_structbuf{5};
+	std::cout<<"Checking [] operator"<<test_structbuf[0]<<"\n";
+	
 	auto temp_struct = test_struct();
+	
 	test_structbuf.push_back(temp_struct);
+	std::cout<<"Checking [] operator"<<test_structbuf[1]<<"\n";
+	std::cout<<"Checking at operator"<<test_structbuf.at(0)<<"\n";
+	
 	test_structbuf.push_back(temp_struct);
+	std::cout<<"Checking at operator"<<test_structbuf.at(1)<<"\n";
 	test_structbuf.push_back(temp_struct);
+	std::cout<<"Checking at operator"<<test_structbuf.at(2)<<"\n";
 	test_structbuf.push_back(temp_struct);
+	std::cout<<"Checking at operator"<<test_structbuf.at(3)<<"\n";
 	test_structbuf.push_back(temp_struct);
+	std::cout<<"Checking at operator"<<test_structbuf.at(4)<<"\n";
 	test_structbuf.push_back(temp_struct);
+	std::cout<<"Checking at operator"<<test_structbuf.at(0)<<"\n";
 	test_structbuf.push_back(temp_struct);
 	test_structbuf.push_back(temp_struct);
 	test_structbuf.push_back(temp_struct);