Re: Ring Buffer & templates

From:
Andrea Crotti <andrea.crotti.0@gmail.com>
Newsgroups:
comp.lang.c++
Date:
Sun, 31 Oct 2010 14:21:54 +0100
Message-ID:
<m139rmxzt9.fsf@ip1-201.halifax.rwth-aachen.de>
Thanks to the suggestions received here now it works pretty well!

It's here below, if you see anything not nice please tell me...

I was now wondering what could be best to do to allow iteration on the
subclasses.
I could
- make "buffer" a protected variable, so in the subclass I can access directly
- just wrap the size method (as I do now) do use the normal for (int
  i..) construct

Is there even a better way?
And if I got with a templated class I can't write the implementation in
another file, but why?

Before I had also a
"T pop();" function, and if I tried to make it virtual it didn't work at
all.

Maybe theoretically it's just wrong to make pop/push virtual since those
should work everywhere in the same way, right?

Thanks

--8<---------------cut here---------------start------------->8---
#ifndef RINGBUFFER_H
#define RINGBUFFER_H

#include <deque>

template<typename T>
class RingBuffer
{
// TODO: see how to make it also iterable
private:
    size_t max_size;
    std::deque<T> buffer;

public:
    RingBuffer(size_t max_size);
    void push(T el);
    size_t size() { return buffer.size(); }
    T operator[](int index) { return buffer[index]; }

    // TODO: move in the implementation below if possible
    friend ostream& operator<<(ostream& s, const RingBuffer<T>& c) {
        s << c;
        return s;
    }
};

template<typename T>
RingBuffer<T>::RingBuffer(size_t max_size) : max_size(max_size)
{}

template<typename T>
void RingBuffer<T>::push(T el)
{
    if (buffer.size() == max_size) {
        buffer.pop_front();
    }
    buffer.push_back(el);
}

#endif /* RINGBUFFER_H */
--8<---------------cut here---------------end--------------->8---

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