The function returns an array of all keys stored in the given dictionary, ignoring dependent parts of key-value pairs. This is especially useful when dictionary is used to form a set of dictinct keys, when dependent parts are fake (typically zeroes). If the destructive parameter is nonzero then the function may avoid copying of keys to the resulting array by moving them out from the dictionary. This is faster but the dictionary will become empty at the end of operation. The destructive parameter does not have any effect if the dictionary is used as a value of more than one variable. Thus it is safe to make this parameter nonzero as soon as the variable passed to the function as dict is no longer in use after the function call and there's no need to inspect the whole program to check if other variables may be affected.
The function returns a vector.