Windows（VS2013 Update 4，VS2015 Update 3）上带有语法标志icase的:: std :: regex_replace与使用字符范围不匹配 [英] ::std::regex_replace with syntax flag icase on Windows (VS2013 Update 4, VS2015 Update 3) does not match using character ranges

问题描述

我在VS2013 Update 4和VS2015 Update 3中使用以下C ++代码，并使用字符范围来尝试不区分大小写地匹配并替换出现的内容：

I use the following C++ code with VS2013 Update 4 and VS2015 Update 3 using a character range to try to match case insensitively and to replace the occurrences:

std::wstring strSource(L"Hallo Welt, HALLO WELT");
std::wstring strReplace(L"ello");
std::regex_constants::syntax_option_type nReFlags =
    std::regex::ECMAScript |
    std::regex::optimize |
    std::regex::icase;
std::wregex  re(L"[A]LLO", nReFlags);
std::wstring strResult = std::regex_replace(strSource, re, strReplace);

wcout << L"Source: \"" << strSource.c_str() << L"\"" << endl
      << L"Result: \"" << strResult.c_str() << L"\"" << endl;

我期望输出：

Source: "Hallo Welt, HALLO WELT"
Result: "Hello Welt, Hello WELT"

但是我得到：

Source: "Hallo Welt, HALLO WELT"
Result: "Hello Welt, HALLO WELT"

为什么不应用字符范围不区分大小写？
为什么似乎找不到第二场比赛并将其替换？

Why the character range didn't get applied caseinsensitive? Why the second match didn't seem to be found and to be replaced?

推荐答案

我觉得这可能是Visual Studio中的错误。如果您从 [A] 中删除​​括号，则效果很好。

I feel like this might be a bug in Visual Studio. If you remove the brackets from [A] it works fine.

std::wregex  re(L"ALLO", nReFlags);

如果您使用 regex_search 很奇怪找到2个匹配项...

Oddly enough if you use a regex_search it finds 2 matches...

std::wregex  re(L"([A]LLO)", nReFlags);
std::wsmatch match;
std::regex_search(strSource, match, re);
for (auto i = 0; i < match.size(); ++i)
    std::wcout << match[i] << "\n";

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