Question

我正在尝试运行the docs中找到的regex_search函数的示例代码。

他们示例中的代码如下：

// regex_search example
#include <iostream>
#include <string>
#include <regex>

int main ()
{
  std::string s ("this subject has a submarine as a subsequence");
  std::smatch m;
  std::regex e ("\\b(sub)([^ ]*)");   // matches words beginning by "sub"

  std::cout << "Target sequence: " << s << std::endl;
  std::cout << "Regular expression: /\\b(sub)([^ ]*)/" << std::endl;
  std::cout << "The following matches and submatches were found:" << std::endl;

  while (std::regex_search (s,m,e)) {
    for (auto x:m) std::cout << x << " ";
    std::cout << std::endl;
    s = m.suffix().str();
  }

  return 0;
}

当我尝试在我的计算机上运行此代码时（我使用的是Ubuntu 16.04并使用g ++编译器），我在IDE上收到m参数的以下警告： Parameter type mismatch: Class 'std::smatch' is not compatible with class 'std::match_results<const char *, std::allocator<std::sub_match<std::basic_string<char, std::char_traits<char>, std::allocator<char>>::const_iterator>>>'

另一个s参数：Parameter type mismatch: Types 'const char *' and 'std::string' are not compatible。

当我尝试编译代码时，我得到了：

./src/launcher.cpp: In function ‘int main()’:
./src/launcher.cpp:18:3: error: ‘smatch’ was not declared in this scope
   smatch m;
   ^
./src/launcher.cpp:18:3: note: suggested alternatives:
In file included from /usr/include/c++/5/regex:61:0,
                 from ./src/launcher.cpp:3:
/usr/include/c++/5/bits/regex.h:1900:50: note:   ‘std::__cxx11::smatch’
   typedef match_results<string::const_iterator>  smatch;
                                                  ^
/usr/include/c++/5/bits/regex.h:1900:50: note:   ‘std::__cxx11::smatch’
./src/launcher.cpp:19:3: error: ‘regex’ was not declared in this scope
   regex e ("\\b(sub)([^ ]*)");   // matches words beginning by "sub"
   ^
./src/launcher.cpp:19:3: note: suggested alternatives:
In file included from /usr/include/c++/5/regex:61:0,
                 from ./src/launcher.cpp:3:
/usr/include/c++/5/bits/regex.h:786:32: note:   ‘std::__cxx11::regex’
   typedef basic_regex<char>    regex;
                                ^
/usr/include/c++/5/bits/regex.h:786:32: note:   ‘std::__cxx11::regex’
./src/launcher.cpp:25:26: error: ‘m’ was not declared in this scope
   while (regex_search (s,m,e)) {
                          ^
./src/launcher.cpp:25:28: error: ‘e’ was not declared in this scope
   while (regex_search (s,m,e)) {
                            ^
./src/launcher.cpp:26:17: error: unable to deduce ‘auto&&’ from ‘m’
     for (auto x:m) std::cout << x << " ";
                 ^
Makefile:21: recipe for target 'launcher.o' failed
make: *** [launcher.o] Error 1

我使用s函数将问题转换为c-string，解决了c_str()参数的问题。不过，我无法使用m参数解决问题。

我尝试将m的类型更改为match_results（这是其模板类），但错误仍然存在。我还尝试将m的类型更改为我的IDE上警告所建议的类型，但问题仍然存在。

我理解问题是m的类型不是函数期望的类型，但我不知道如何解决它。

有人对如何解决这个问题有任何建议吗？

我的主要目标是调整该代码以提取包含某个子字符串的特定字符串，因此如果有人对如何做到这一点有任何建议，我将非常感激。

regex - 在C ++中使用regex_search函数时参数类型不匹配

0 个答案: