+1 to Ben Craig's request for a motivational example. A couple of other points to consider:* Could it be a static member function rather than a const member function? If I understand, this seems like it might be data that you'd want to use to create a container, rather than a question you'd want to ask of an existing container.* Either way, I imagine that it could and should be a constexpr function.Regards,Ben SaksSent from my Galaxy
-------- Original message --------From: Ben Craig via SG14 <sg14_at_[hidden]> Date: 11/25/21 11:46 AM (GMT-05:00) To: sg14_at_[hidden] Cc: Ben Craig <ben.craig_at_[hidden]> Subject: Re: [SG14] sizeof_block_metadata function, colony/hive,
  advice wanted If you can provide a short, motivational chunk of code that shows how it would be used, then that would make it a lot easier to answer the question about whether it's useful or not. I suspect the function may be providing something that is easy for the implementation to provide, but very hard for a user to use.I suspect that this is trying to help the user solve an optimization problem, where they are trying to minimize the amount of total memory used for a given range of element counts. If that's the case, then write a short code snippet that either solves, or hints at the solution to that problem. > -----Original Message-----> From: SG14 <sg14-bounces_at_[hidden]> On Behalf Of Matt Bentley via> SG14> Sent: Wednesday, November 24, 2021 7:35 PM> To: Low Latency:Game Dev/Financial/Trading/Simulation/Embedded Devices> <sg14_at_[hidden]>> Cc: Matt Bentley <mattreecebentley_at_[hidden]>> Subject: [EXTERNAL] [SG14] sizeof_block_metadata function, colony/hive,> advice wanted> > Hi all,> thinking about including a> size_type sizeof_block_metadata(const size_t block_size)> > function for colony/hive, as this would allow the user to ascertain the> amount of memory used by a memory block's metadata in colony (including> skipfield), given the number of elements stored in that memory block.> This is less important for colony which is a fixed implementation, more> important for std::hive which could potentially have many alternative> implementations and these might not be visible to the user in text form.> > The idea was that if someone knows how much memory is used by each> block outside of the actual memory used to store the elements, that might> aid in terms of knowing how much cache space is used by the metadata and> people might be able to make better decisions about the min/max capacities> of memory blocks (if they are specifying these manually) on that basis.> > The function would throw an exception if the block_size specified was> outside the minimum/maximum block capacity ranges.> > My main question to you is whether this function is worth including - as it> adds yet another function to the codebase.> Thanks,> M@> > > _______________________________________________> SG14 mailing list> SG14_at_[hidden]> https://urldefense.com/v3/__https://lists.isocpp.org/mailman/listinfo.cgi/sg> 14__;!!FbZ0ZwI3Qg!_EmqRo6oE_K3_0kspLt95nQkSwn6ReF6w24SgNk6c4-> tKwgxy1B_QABcfeZ_$_______________________________________________SG14 mailing listSG14_at_[hidden]://lists.isocpp.org/mailman/listinfo.cgi/sg14