Alternative to Base.summarysize?

I was wondering if there were any alternative to Base.summarysize, for trying to show the memory cost of an object.
It looks like it is based on sizeof, instead of returning the actual amount of memory allocated for that object.
For example, if you ask for the summarysize of a 3x3 Float64 array, it returns 72, which doesn’t reflect the real allocated size, which is at least 112 bytes on a 64-bit system, due to the overhead of the Array type itself.
This also doesn’t reflect the amount of actually allocated either, just the portion that is visible.


I don’t see anything to that effect in base. Ref: related discussion and suggestion.