/*
 *  call-seq:
 *     dvector.uniq -> a_dvector
 *  
 *  Returns a new vector by removing duplicate elements from _dvector_.
 *  Remove the element if there is a later one in the vector that is equal to it.
 *     
 *     a = Dvector[ 1.1, 3.8, 1.7, 3.8, 5 ]
 *     a.uniq              ->   Dvector[1.1, 1.7, 3.8, 5]
 */ VALUE dvector_uniq(VALUE ary) {