C++中的"%:"和"%:%:"如何使用？

Question

可能这是C++11的内容，但是不明白用法 像G++中可以用""代替"}"，"<:"代替"["，":>"代替"]" 经过测试，微软的编译器中并未实现这个语法 "%:"和"%:%:"的出处是 http://www.externsoft.ch/media/swf/cpp11-iso.html#preprocessing_op_or_punc

Answer 1

The keyboards we use are all standard American keyboards. However, in some countries, many keyboard layouts do not have {, so you can use <% instead of {.

§6.4.6-3 (C99)

In all aspects of the language, the six tokens

<: :> %: %:%:

behave, respectively, the same as the six tokens

[ ] { } # ##

So:

• %: is #
• %:%: Just ##

Download ISOIEC 9899-201x-C language standard specification.pdf