shuffle

/*
 *  call-seq:
 *     array.shuffle -> an_array
 *  
 *  Returns a new array with elements of this array shuffled.
 *     
 *     a = [ 1, 2, 3 ]           #=> [1, 2, 3]
 *     a.shuffle                 #=> [2, 3, 1]
 */

static VALUE
rb_ary_shuffle(VALUE ary)
{
    ary = rb_ary_dup(ary);
    rb_ary_shuffle_bang(ary);
    return ary;
}