text: 'use strict';
  
  // there's 3 implementations written in increasing order of efficiency
  
  // 1 - no Set type is defined
  
  function uniqNoSet(arr) {
  	var ret = [];
  
  	for (var i = 0; i < arr.length; i++) {
  		if (ret.indexOf(arr[i]) === -1) {
  			ret.push(arr[i]);
  		}
  	}
  
  	return ret;
  }
  
  // 2 - a simple Set type is defined
  function uniqSet(arr) {
  	var seen = new Set();
  	return arr.filter(function (el) {
  		if (!seen.has(el)) {
  			seen.add(el);
  			return true;
  		}
  
  		return false;
  	});
  }
  
  // 3 - a standard Set type is defined and it has a forEach method
  function uniqSetWithForEach(arr) {
  	var ret = [];
  
  	new Set(arr).forEach(function (el) {
  		ret.push(el);
  	});
  
  	return ret;
  }
  
  // V8 currently has a broken implementation
  // https://github.com/joyent/node/issues/8449
  function doesForEachActuallyWork() {
  	var ret = false;
  
  	new Set([true]).forEach(function (el) {
  		ret = el;
  	});
  
  	return ret === true;
  }
  
  if ('Set' in global) {
  	if (typeof Set.prototype.forEach === 'function' && doesForEachActuallyWork()) {
  		module.exports = uniqSetWithForEach;
  	} else {
  		module.exports = uniqSet;
  	}
  } else {
  	module.exports = uniqNoSet;
  }