From the NannyMUD documentation

LAST CHANGE

2001-10-12

FUNCTION

NAME
        recursive_copy - Copy a mapping/array and all sub-parts.


SYNTAX
        mixed recursive_copy(mixed arg)

DESCRIPTION
        This simulated efun copies an array or mapping, including all
        sub-parts, be they arrays, ints, mappings, ...


NOTE
	Note that the recursive nature of this function might trigger
	one of the runtime errors 'too deep recursion' and 'too long
	evaluation' if fed too large, deep or complex data.