问题描述
Hi NG，
我正在开发一个软件，它基本上包含一个循环，
，其中包含2个部分。这两个部分基本上是相同的，
但是它们在某些变量中有所不同。所以我将变量从foo0
和foo1更改为foo [2]，因此我可以将它们编入索引。这样我可以通过
循环两次，但是在0和1之间切换索引。
这很简单。我是这样做的：
int idx;
for（idx = 0 ;; idx =！idx）
{
do_something_with（foo [idx]）;
if（somestatement）break;
}
我的问题是：标准是否保证idx =！idx总是在1或0中产生
？如果我希望编译器循环展开它，
会有用吗？或者这只适用于具有明确的
结束语句而不是休息的for循环？
提前致谢，
马克
Hi NG,
I am developing a piece of software, which contains basicly one loop,
which consinsts of 2 parts. Thos two parts are again basicly the same,
but they deiffer in some variables. So I changed the variables from foo0
and foo1 to foo[2], so I can index them. This way I can run through the
loop two times more, but switch the index between 0 and 1.
This is pretty easy. I did it this way:
int idx;
for(idx=0;;idx=!idx)
{
do_something_with(foo[idx]);
if(somestatement) break;
}
my question is: Does the standard guarantee that idx=!idx always result
in a 1 or a 0? And if I would want the compiler to loop unroll this,
would that work? Or does that only work for a for loop which has a clear
end statement in stead of a break?
Thanks in advance,
Mark
推荐答案
我不知道。 ：-\
-
Russell Hanneken
是的。然而，你可以有一个更简单和更清晰的循环：
for（idx = 0; idx< 2; idx ++）{
do_something_with（foo [ idx]）;
}
（注意几年前空白的短缺结束）
-
回复应该是新闻组
Chuck Falconer度假。
Yes. However you can have a much simpler and clearer loop with:
for (idx = 0; idx < 2; idx++) {
do_something_with(foo[idx]);
}
(Note that the blank shortage ended several years ago)
--
Replies should be to the newsgroup
Chuck Falconer, on vacation.
这篇关于"智能"索引的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！