@dlsflh https://www.rfc-editor.org/rfc/rfc2119.html
1. MUST This word, or the terms "REQUIRED" or "SHALL", mean that the
definition is an absolute requirement of the specification.

2. MUST NOT This phrase, or the phrase "SHALL NOT", mean that the
definition is an absolute prohibition of the specification.

3. SHOULD This word, or the adjective "RECOMMENDED", mean that there
may exist valid reasons in particular circumstances to ignore a
particular item, but the full implications must be understood and
carefully weighed before choosing a different course.

4. SHOULD NOT This phrase, or the phrase "NOT RECOMMENDED" mean that
there may exist valid reasons in particular circumstances when the
particular behavior is acceptable or even useful, but the full
implications should be understood and the case carefully weighed
before implementing any behavior described with this label.

@icyalala http://port70.net/~nsz/c/c99/n1256.html#4p2 If a ''shall'' or ''shall not'' requirement that appears outside of a constraint is violated, the behavior is undefined.

@betatabe must 才是必须，shall 没有强制性，早期的编译器实现就是没有初始化的，所以都需要调用 memset

只要圣上在位一天，就还能再跌一天

@longbowape ^[\u4e00-\u9fa5\d\w- ]*[\u4e00-\u9fa5\d\w-]+[\u4e00-\u9fa5\d\w- ]*$

^[\u4e00-\u9fa5\d\w ]*[\u4e00-\u9fa5\d\w]+[\u4e00-\u9fa5\d\w ]*$

爱死机第一季

地狱边境

“来喝了这碗鸡汤，多喝几次就不会过敏了啊，乖，都是为了你好！” “你这个孩子怎么这么不中用啊，我辛辛苦苦把你养这么大怎么就这么死了啊！”

@R18 headcount https://en.wiktionary.org/wiki/headcount

豆瓣租房小组多看看，自如还是有些贵了，而且万一踩到雷也麻烦

@tyrealgray 厉害，学到了

ori and the blind forest

the sound of silence

新冠毁了多少人的生活，唉

@mostkia 只要能分享，就一定会被监管吧