bidirectional map

[bioinfornatics]

On Tuesday, 12 November 2013 at 09:10:07 UTC, Andrea Fontana 
wrote:
> On Tuesday, 12 November 2013 at 01:14:47 UTC, bioinfornatics 
> wrote:
>> Dear,
>> I am looking for a bidirectional map i.e 
>> http://en.wikipedia.org/wiki/Bidirectional_map
>>
>> My seach into D documentation seem to said to me that this 
>> structure is not implemented.
>>
>> Something like (for primary idea):
>>
>>
>> struct BidirectionalMap(T,U){
>>    private:
>>        T[U] _forwardHash;
>>        U[T] _reverseHash;
>>
>>    public:
>>
>>        @safe
>>        void opIndeyAssign( T k, U v){ // pure?
>>            _forwardHash[k] = v;
>>            _reverseHash[v] = k;
>>        }
>>
>>
>>        @property
>>        BidirectionalMap!(T,U) dup(){
>>            return BidirectionalMap!(T,U)( this );
>>        }
>> }
>
> Maybe we can get a better (faster/lighter) implementation if 
> T==U (using sorted (T,T) tuples?)
>
> By the way:
>
> map[10] = 5; //   =>  _forwardHash[10] = 5; _reverseHash[5] = 
> 10;
> map[10] = 3; //   =>  _forwardHash[10] = 3; _reverseHash[3] = 
> 10;
>
> So:
> _reverseHash[5] == 10; // True, it should not, should it?

Maybe using Variant will allow to use 1 associative array