Expression Template
http://en.wikibooks.org/wiki/More_C%2B%2B_Idioms/Expression-template
http://www.google.com/search?q=c%2B%2B+%E6%83%B0%E6%80%A7%E6%B1%82%E5%80%BC&btnG=Google+%E6%90%9C%E7%B4%A2&hl=zh-CN&client=firefox-a&rls=org.mozilla%3Azh-CN%3Aofficial&hs=6Iu&sa=2
http://www.ibm.com/developerworks/cn/linux/l-lazyprog.html
http://zh.wikipedia.org/zh-cn/%E6%9E%81%E5%B0%8F%E5%8C%96%E6%B1%82%E5%80%BC