Re: [boost] Re: circular_buffer question

From: Jan Gaspar (jano_gaspar_at_[hidden])
Date: 2004-04-13 07:18:28

Hi Pavel!

> 
> 2. operator[] for circular_buffer itself:
> 
>    circular_buffer<int> b(10);
>    b.push_back(10);
>    b.push_back(20);
>    b.push_back(33);
>    int x = b[-1];  // this would return value 30,
> the last one
>    x = b[-2]; // would return 20
> 
> This would be new feature, not available in current
> standard ontainers. I remember some language
> (forgot name) provides it.
> 
> I personally would like to have this feature
> and have it in std::vector/deque too.
> 
I think this can be solved (for any container) by some
kind of adaptor:

template <class Container> ring {
public:

 // constructor
 ring(const Container& c);

 // element access
 Container::value_type& operator[] (int index) const;
};

 
> 
> 3. incrementing/decrementing circular_buffer
>     iterator with automatic wrap-around:
> 
>     I think this (wrap-around) should not be
>     allowed:
>     - it could hide errors
>     - it suggests circular-linked-list semantics
>       (and one can then ask for rotate())
> 

There is a cycle_iterator (yet another
iterator_adaptor application) in the yahoo files
section which can solve this problem.

Jan

        
                
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