c++14是否在c++中添加了新的关键字?-IsC++14addingnewkeywordstoC++?

136  

Table 4 (Keywords) in N3936 (C++14):

表4(关键词)N3936 (c++ 14):

alignas           continue          friend            register          true
alignof           decltype          goto              reinterpret_cast  try
asm               default           if                return            typedef
auto              delete            inline            short             typeid
bool              do                int               signed            typename
break             double            long              sizeof            union
case              dynamic_cast      mutable           static            unsigned
catch             else              namespace         static_assert     using
char              enum              new               static_cast       virtual
char16_t          explicit          noexcept          struct            void
char32_t          export            nullptr           switch            volatile
class             extern            operator          template          wchar_t
const             false             private           this              while
constexpr         float             protected         thread_local
const_cast        for               public            throw

Table 4 in N3337 (C++11):

表4 N3337 (C++11):

alignas           continue          friend            register          true
alignof           decltype          goto              reinterpret_cast  try
asm               default           if                return            typedef
auto              delete            inline            short             typeid
bool              do                int               signed            typename
break             double            long              sizeof            union
case              dynamic_cast      mutable           static            unsigned
catch             else              namespace         static_assert     using
char              enum              new               static_cast       virtual
char16_t          explicit          noexcept          struct            void
char32_t          export            nullptr           switch            volatile
class             extern            operator          template          wchar_t
const             false             private           this              while
constexpr         float             protected         thread_local
const_cast        for               public            throw

...which is a long-winded way of saying "no".

…这是一个冗长的说“不”的方式。

(override and final are "identifiers with special meaning" and are listed in Table 3; and etc. are "alternative representations...for certain operators and punctuators" and are listed in Table 5. Neither table changed between C++11 and C++14.)

(override和final是“具有特殊含义的标识符”，列于表3中;等等是“替代表征……”表5列出了某些操作符和标点符号。这两个表在c++ 11和c++ 14之间都没有变化。

85  

I'm posting this answer for the sake of giving tools for finding answers to similar questions.

我发布这个答案是为了提供工具来寻找类似问题的答案。

The standard draft is currently kept in a public GitHub repository. That means you can ask this question to GitHub itself!

标准草案目前保存在一个公开的GitHub存储库中。这意味着你可以问GitHub自己这个问题!

The keywords table is on the file source/lex.tex. If you do a blame on it, we can find that the last change to the keywords table took place back in August 2011 (it's actually the first commit: that table hasn't changed since the repo went live around the time C++11 was being finalised).

关键字表位于文件源/lex.tex上。如果你对此负责，我们可以发现，关键字表的最后一个变更发生在2011年8月(这实际上是第一次提交:自从repo在C++11事件结束之后，这个表一直没有改变)。

Alternatively we can ask GitHub to compare the two drafts that were sent for ballot for both versions of the standard: N3337 and N3936. A diff between those two shows that the changes to lex.tex did not change anything in the keywords table.

或者，我们可以要求GitHub比较两种版本的投票结果:N3337和N3936。这两者之间的差异表明lex的变化。tex没有更改关键字表中的任何内容。

33  

No new keywords will be added with C++14. This is unsurprising as C++14 is intended as a small upgrade to C++11 mainly involved in cleaning up bugs and making small, low impact, improvements. The next major change is likely to be C++'17' where I would expect new keywords once more.

没有新的关键字将添加到c++ 14。这并不奇怪，因为c++ 14打算作为c++ 11的小型升级，主要用于清理bug并进行小的、低影响的改进。下一个主要的变化可能是c++的“17”，在这里我将再次期待新的关键字。

The C++ Standards Committee tends to shy away from adding new keywords to the language, yet with C++11 that was not the case.

c++标准委员会倾向于避免在语言中添加新的关键字，但是c++ 11不是这样的。

I think it's worth considering why the committee shies away from adding new keywords (and co-incidentally why you are wrong to include auto on your list). The main problem with new keywords is that in C++ you can't use a keyword as an identifier which means that adding a new keyword breaks existing code. Repurposing auto, then, doesn't break their rule because no existing code could use auto as an identifier anyway.

我认为值得考虑的是，为什么委员会不愿增加新的关键词(顺便说一下，为什么你把auto包括在你的列表中是错误的)。新关键字的主要问题是，在c++中，不能使用关键字作为标识符，这意味着添加新关键字会破坏现有代码。因此，重新利用auto并不会破坏他们的规则，因为任何现有代码都不能使用auto作为标识符。

So in order to accept a new keyword there needs to be a justification that outweighs the cost of a potential clash with existing code and no sensible way to implement the same thing without a new keyword. In the case of C++11, the committee accepted a few proposals that required new keywords since they felt that that the benefit outweighed the cost not because they don't hate to add new keywords.

因此，为了接受一个新的关键字，需要有一个比潜在的与现有代码冲突的代价更大的理由，并且没有一个没有新关键字的合理方法来实现相同的东西。在c++ 11的例子中，委员会接受了一些需要新的关键字的建议，因为他们认为好处大于成本，而不是因为他们不喜欢添加新的关键字。

It's also why, if you look down the list you gave, each one is a compound keyword since that reduces the chance that they'll clash with existing identifiers.

这也是为什么，如果您查找您给出的列表，每个都是一个复合关键字，因为这减少了它们与现有标识符冲突的可能性。