Are there any situations where code would have a sequence point in c++11 but not c++03?

问题

Now that the new c++11 standard has made changes in how sequence points are described I'm trying to find out exactly what has been changed between c++03 and c++11.

In particular, are there any situations where code that looks the same would have a sequence point in c++11 but not c++03?

回答1:

There are no sequence points in C++11, rather there are sequenced before and sequenced after relations.

Here are some trivial examples wherein behavior differ between C++03 and C++11

int x = 10;
++++x; // well defined in C++11

int x = 10;
x = ++x +1; //well defined in C++11

Why? Have a look at this answer and related threads.

回答2:

I think the best known example is the pre-increment operator.

int i = 0;
++ ++ ++ i;

In C++03, this would be UB, and in C++11, each assignment is ordered before the next evaluation.

Searching the Standard for differences is tough because they got rid of the "sequence point" terminology in favor of "ordered before" and the like, and rewrote much of the rules from scratch.

来源：https://stackoverflow.com/questions/9293595/are-there-any-situations-where-code-would-have-a-sequence-point-in-c11-but-not