justasmasiulis/circular_buffer

A constexpr STL style circular buffer implementation

circular_buffer

A simple circular buffer implementation. Tests and documentation still needs work but I'd say it's working properly and the api is STL style.

Small example

#include "circular_buffer.hpp"

// constructors accept iterators, initializer lists or count + element
jm::circular_buffer<int, 4> cb{ 1,2,3 };
cb.push_back(4);  // 1234
cb.push_front(0); // 0123
cb.push_back(5);  // 1235
cb.pop_front(); // 235 also supports pop_back
// iterators are supported and constexpr ( except reverse ones because std::reverse_iterator ) 
for(auto& value : cb)
    std::cout << value; 
cb.size(); // 3
cb.max_size() // 4
cb.clear(); // 
// this can also be done constexpr.
// using c++14 the only non constexpr api is emplace_back and emplace_front

How to use

The library is a single header so all you need to do is copy the header to your directory and include it.

By default it uses c++ 11 features. However you can define JM_CIRCULAR_BUFFER_CXX_14 for most of the circular_buffer to become constexpr or JM_CIRCULAR_BUFFER_CXX_OLD for c++98 ( maybe even lower? ) support.

It is also possible to micro optimize the buffer ( on clang and gcc only ) if you know if it will likely be full or not by using JM_CIRCULAR_BUFFER_LIKELY_FULL OR JM_CIRCULAR_BUFFER_UNLIKELY_FULL.

circular_buffer's Issues

Exception when using user defined class with stl containers as attribute

May suggest a test that fails?
Insert a vector as an attribute

struct leak_checker {

leak_checker() { ++num_constructions; }

~leak_checker() { ++num_deletions; }

leak_checker(const leak_checker&) { ++num_constructions; }

leak_checker(leak_checker&&) { ++num_constructions; }

leak_checker& operator=(const leak_checker&) = default;
leak_checker& operator=(leak_checker&&) = default;

std::vector<float> numbers;

};

Explanation: What returns pop_front after producer exceeds ringbuffer size ?

The documentation is not overly verbose.

I cannot read, what is returned via pop_front() after the ring buffer producer has already overwritten the current reading position element. Is the reading position moved as well ? Could you explain ?

How to extract the numbers in a specific position gracefully?

Thank you very much for your project.

circular_buffer<int, 4> cb{1, 2, 3};
cb.push_back(4); 
cb.push_back(5);
// 2,3,4,5
std::cout << "cb back():" << cb.back() << " cb back()-1:" << *(cb.data() + 3) <<  *(&cb.back() - 1) << std::endl;

Is there a more beautiful way?

Can the size template parameter 'N' be made into a variable?

First, thanks for the nice package.

My request is whether the template parameter N be made into a variable rather a constant? I have use cases that the size of the buffer is unknown, and is set in a configuration file. It is one less constraint for the circular buffer class. Let me know how you think.

Create buffer from user defined class

I couldn't use your circular_buffer with any of my defined types. For instance, none of the classes defined here https://en.cppreference.com/w/cpp/language/rule_of_three
I am using msvc 2017 and it throws an error nad a warning:

• warning C4624: 'jm::circular_buffer<my_type,3>': destructor was implicitly defined as deleted
• 'jm::circular_buffer<my_type,3>::~circular_buffer(void)': attempting to reference a deleted function

Thanks