[LLVMdev] llvm::DenseSet with reverse iterator

[Vassil Vassilev]

Hi,
   Thanks a lot for the help!
   It seems that the SmallSetVector is the ADT I need (interface-wise). 
Is more efficient than llvm::UniqueVector?
   In my use case I have to insert a new element in the structure only 
if the element is unique. I hardly expect more than 32 elements. Do you 
think I gain a lot if I use the SmallSetVector instead of using 
SmallVector + slow searching on every push_back?
Vassil
On 7/12/12 6:23 PM, Michael Ilseman wrote:
> Something that might interest you is the SetVector, which as its name
> implies is both a set and a vector paired together. You get the
> advantage of doing set-like operations (search) on the set and
> vector-like operations (iteration, random access) on the vector, but
> at the cost of paying the price for both data structures when
> modifying the structure (and double the memory). This seems like it
> might be more heavy-weight than you needed, but it might serve your
> purposes. The iteration order is the insertion order; if you want some
> other ordering and stronger iterators, you might have to consider
> std::set.
>
> [1] http://llvm.org/doxygen/SetVector_8h_source.html
> [2] http://llvm.org/docs/ProgrammersManual.html#dss_setvector
>
> On Thu, Jul 12, 2012 at 10:04 AM, Owen Anderson <resistor at mac.com> wrote:
>> Reverse iteration doesn't really make sense for DenseSet, since its iteration order isn't meaningful to begin with...
>>
>> --Owen
>>
>> On Jul 12, 2012, at 8:20 AM, Vassil Vassilev wrote:
>>
>>> Hi,
>>>    I need a data structure which has fast search and I can walk it
>>> forward and backward. Is there something like that in LLVM ADT which am
>>> not aware of? And if not can I implement it in llvm::DenseSet?
>>> Vassil
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