The concept of a "descriptor" as an object for memory accesses that helps with bounds checking and preventing memory overruns was borrowed lock stock and barrel (including the terminology) into the Symbian OS's C++ API - classes TDesC, TDes, TPtrC, etc. Contrary to the amount of bitching one hears, they were a pleasure to work with, for me, due to the confidence due to bounds checking, efficient representation (perfectly ok to stack copy them) and it was just convenient to have to never pass additional length arguments anywhere internally.

... ok 'nuff fond reminiscing.