c++ - boost::regex 与 UTF-8 不区分大小写匹配(例如，大写与小写变音)

Question

在构建支持 Unicode 国际组件 (ICU) 的 boost::regex 1.52 版库后，匹配不区分大小写的正则表达式似乎无法按预期处理大写和小写德语变音字符。

static const std::string pattern("^.*" "\303\226" ".*$");
static const std::string   test1("SCH" "\303\226" "NE");
static const std::string   test2("sch" "\303\266" "ne");
static const boost::regex exp(pattern, boost::regex::icase);
const char *result = (boost::regex_match(test1, exp)) ? "Match" : "NoMatch";
std::cout << "Testing \"" << test1 << "\" against pattern \"" << pattern 
    << "\" : " << result << std::endl;
result = (boost::regex_match(test2, exp)) ? "Match" : "NoMatch";
std::cout << "Testing \"" << test2 << "\" against pattern \"" << pattern 
    << "\" : " << result << std::endl;

产量:

Testing "SCHÖNE" against pattern "^.*Ö.*$" : Match
Testing "schöne" against pattern "^.*Ö.*$" : NoMatch

Answer 1

Working with Unicode and ICU string types .

Example on LWS .

#include <iostream>
#include <boost/regex.hpp>
#include <boost/regex/icu.hpp>
int main()
{
   static const std::string pattern("^.*" "\303\226" ".*$");
   static const std::string   test1("SCH" "\303\226" "NE");
   static const std::string   test2("sch" "\303\266" "ne");
   static const boost::u32regex exp=boost::make_u32regex(pattern, boost::regex::icase);
   const char *result = (boost::u32regex_match(test1, exp)) ? "Match" : "NoMatch";
   std::cout << "Testing \"" << test1 << "\" against pattern \"" << pattern 
      << "\" : " << result << std::endl;
   result = (boost::u32regex_match(test2, exp)) ? "Match" : "NoMatch";
   std::cout << "Testing \"" << test2 << "\" against pattern \"" << pattern 
      << "\" : " << result << std::endl;
}