[英]regex_token_iterator *it++ bug?
for following code: 用于以下代码:
#include<iostream>
#include<regex>
using namespace std;
int main(int argc, char *argv[])
{
regex reg("/");
string s = "Split/Values/Separated/By/Slashes";
sregex_token_iterator it{std::begin(s), std::end(s), reg, -1};
sregex_token_iterator end;
while(it != end)
{
cout << *it++ << endl;
}
return 0;
}
should output: 应该输出:
Split
Values
Separated
By
Slashes
but it outputs this: 但它输出这个:
Values
Separated
By
Slashes
the main code may be problem is *it++
, if I write cout << *it << endl;++it;
主要代码可能是问题是*it++
,如果我写cout << *it << endl;++it;
,it work right. ,它的工作正常。
when I change the stand c++11 regex to boost-regex, *it++
also work right. 当我将stand c ++ 11 regex更改为boost-regex时, *it++
也正常工作。
I have check the head of regex, I think the operator++(int)
function has no problem. 我检查了正则表达式的头部,我认为operator++(int)
函数没有问题。
my clang version is 我的铿锵版是
Apple LLVM version 5.0 (clang-500.2.79) (based on LLVM 3.3svn)
Target: x86_64-apple-darwin13.0.0
Thread model: posix
Is there anyone have such problem? 有人有这样的问题吗?
Is there a bug in clang? clang中有错误吗?
I found that it's a libc++ implementation bug. 我发现这是一个libc ++实现错误。
Go to regex, insert the following two lines 转到正则表达式,插入以下两行
regex_token_iterator operator++(int)
{
regex_token_iterator __t(*this);
std::cout << "test---" << *__t << "---test" << endl;
++(*this);
std::cout << "test---" << *__t << "---test" << endl;
return __t;
}
you find that the value of *__t changed after ++(*this) ! 你发现++(* this)之后* __ t的值发生了变化!
Further dig into you will find that, 进一步挖掘你会发现,
*__t is actually implemented by returning internal value_type pointer _ result , while _ result actually points to &_ position ->prefix(), which is the address of match_results' _ prefix object, the address of this object never changed, but the content of it changed. * __ t实际上是通过返回内部value_type指针_ 结果来实现的 ,而_ result实际指向&_ position - > prefix(),这是match_results'_ 前缀对象的地址,这个对象的地址从未改变,但是内容它改变了。
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