javascript array unique

function uniquePrimitives(array){
  var hash = Object.create(null),
      out = [],
      i = array.length;

  while (i--) {
    if (!hash[array[i]]) {
      hash[array[i]] = true;
      out.push(array[i]);
    }
  }

  return out;
}






var unique = function(){
  var hasOwn = {}.hasOwnProperty,
      uids = {};

  function uid(){
    var str = '_' + Math.random().toString(36);
    if (str in uids)
      return uid();

    uids[str] = true;
    return str;
  }

  function unique(array){
    var strings = {}, numbers = {}, others = {},
        tagged = [], failed = [],
        count = 0, i = array.length,
        item, type;

    var id = uid();

    while (i--) {
      item = array[i];
      type = typeof item;
      if (item == null || type !== 'object' && type !== 'function') {
        // primitive
        switch (type) {
          case 'string': strings[item] = true; break;
          case 'number':
            if (1 / item === -Infinity)
              // negative zero
              others[item] = item;
            else
              numbers[item] = true;
            break;
          default: others[item] = item; break;
        }
      } else {
        // object
        if (!hasOwn.call(item, id)) {
          try {
            // set key ON each object tagging it as "seen"
            item[id] = true;
            tagged[count++] = item;
          } catch (e){
            if (failed.indexOf(item) === -1)
              failed[failed.length] = item;
          }
        }
      }
    }

    // remove the tags
    while (count--)
      delete tagged[count][id];

    tagged = tagged.concat(failed);
    count = tagged.length;

    // append primitives to results
    for (i in strings)
      if (hasOwn.call(strings, i))
        tagged[count++] = i;

    for (i in numbers)
      if (hasOwn.call(numbers, i))
        tagged[count++] = +i;

    for (i in others)
      if (hasOwn.call(others, i))
        tagged[count++] = others[i];

    return tagged;
  }

  return unique;
}();