[Haskell-cafe] Queue which tracks actual in-memory element size?

Hi all, So we have the TBQueue[1] which tracks the number of elements, but does anyone know if there's an equivalent queue which the actual combined size of the elements? (I'd be quite happy if it used "gsize" or similar, but I suppose the ideal would be if I could supply a "size estimator" function.) It seems like an obvious generalization of TBQueue[2], but my Google-fu is letting me down at the moment. Regards, --- [1] https://hackage.haskell.org/package/stm-2.4.4.1/docs/Control-Concurrent-STM-... [2] TBQueue would be the equivalent of estimating every element to have size 1.