As far as I know, there are no "sizeOf" methods available in
Java (or CF as a result), like you would find in languages like C
or C++. This is largely due to how much differently Java handles
memory allocation than other languages (e.g...heaps, garbage
collection, etc)
Unfortunately, the best you could do would be to write a
custom routine to recursively crawl through the structure and and
count the number of characters present in all of the strings it
contains. (assuming this is a structure of purely "simple" data
types). You could then provide a rough estimation on bytes
allocated to the struct based on the total sum of characters it
contains.