C++ regex::empty方法代码示例

/**
 * Generic tokenizer.
 * Splits source into tokens and tries to lexically cast them to TARGET.
 * If that fails, boost::bad_lexical_cast is thrown.
 * \param source the source string to be split up
 * \param separator regular expression to delimit the tokens (defaults to \\s+)
 * \param prefix regular expression for text to be removed from the string before it is split up
 * ("^" if not given, will be added at the beginning)
 * \param postfix regular expression for text to be removed from the string before it is split up
 * ("$" if not given, will be added at the end)
 * \returns a list of the casted tokens
 */
template<typename TARGET> std::list<TARGET> stringToList(
	std::string source, const boost::regex &separator,
	boost::regex prefix, boost::regex postfix )
{
	std::list<TARGET> ret;
	assert( ! separator.empty() );

	if ( ! prefix.empty() ) {
		if ( prefix.str()[0] != '^' )
			prefix = boost::regex( std::string( "^" ) + prefix.str(), prefix.flags() );

		source = boost::regex_replace( source, prefix, "", boost::format_first_only | boost::match_default );
	}

	if ( ! postfix.empty() ) {
		if ( postfix.str()[postfix.size() - 1] != '$' )
			postfix = boost::regex( postfix.str() + "$", postfix.flags() );

		source = boost::regex_replace( source, postfix, "", boost::format_first_only | boost::match_default );
	}

	boost::sregex_token_iterator i = boost::make_regex_token_iterator( source, separator, -1 );
	const boost::sregex_token_iterator token_end;

	while ( i != token_end ) {
		ret.push_back( boost::lexical_cast<TARGET>( ( i++ )->str() ) );
	}

	return ret;
}

	bool operator()(const boost::regex& r) const {
		try {
			return !r.empty() && boost::regex_search(str, r);
		} catch(const std::runtime_error&) {
			// most likely a stack overflow, ignore...
			return false;
		}
	}

void bcp_implementation::copy_path(const fs::path& p)
{
   assert(!fs::is_directory(m_boost_path / p));
   if(fs::exists(m_dest_path / p))
   {
      std::cout << "Copying (and overwriting) file: " << p.string() << "\n";
     fs::remove(m_dest_path / p);
   }
   else
      std::cout << "Copying file: " << p.string() << "\n";
   //
   // create the path to the new file if it doesn't already exist:
   //
   create_path(p.branch_path());
   //
   // do text based copy if requested:
   //
   if(p.leaf() == "Jamroot")
   {
      static std::vector<char> v1, v2;
      v1.clear();
      v2.clear();
      std::ifstream is((m_boost_path / p).c_str());
      std::copy(std::istreambuf_iterator<char>(is), std::istreambuf_iterator<char>(), std::back_inserter(v1));

      static boost::regex libname_matcher;
      if(libname_matcher.empty())
      {
         libname_matcher.assign("boost_");
      }

      regex_replace(std::back_inserter(v2), v1.begin(), v1.end(), libname_matcher, m_namespace_name + "_");
      std::swap(v1, v2);
      v2.clear();

      std::ofstream os;
      if(m_unix_lines)
         os.open((m_dest_path / p).c_str(), std::ios_base::binary | std::ios_base::out);
      else
         os.open((m_dest_path / p).c_str(), std::ios_base::out);
      os.write(&*v1.begin(), v1.size());
      os.close();
   }
   else if(m_namespace_name.size() && m_lib_names.size() && is_jam_file(p))
   {
      static std::vector<char> v1, v2;
      v1.clear();
      v2.clear();
      std::ifstream is((m_boost_path / p).c_str());
      std::copy(std::istreambuf_iterator<char>(is), std::istreambuf_iterator<char>(), std::back_inserter(v1));

      static boost::regex libname_matcher;
      if(libname_matcher.empty())
      {
         std::string re = "\\<";
         re += *m_lib_names.begin();
         for(std::set<std::string>::const_iterator i = ++m_lib_names.begin(); i != m_lib_names.end(); ++i)
         {
            re += "|" + *i;
         }
         re += "\\>";
         libname_matcher.assign(re);
      }

      regex_replace(std::back_inserter(v2), v1.begin(), v1.end(), libname_matcher, get_new_library_name(m_namespace_name));
      std::swap(v1, v2);
      v2.clear();

      std::ofstream os;
      if(m_unix_lines)
         os.open((m_dest_path / p).c_str(), std::ios_base::binary | std::ios_base::out);
      else
         os.open((m_dest_path / p).c_str(), std::ios_base::out);
      os.write(&*v1.begin(), v1.size());
      os.close();
   }
   else if(m_namespace_name.size() && is_source_file(p))
   {
      //
      // v1 hold the current content, v2 is temp buffer.
      // Each time we do a search and replace the new content 
      // ends up in v2: we then swap v1 and v2, and clear v2.
      //
      static std::vector<char> v1, v2;
      v1.clear();
      v2.clear();
      std::ifstream is((m_boost_path / p).c_str());
      std::copy(std::istreambuf_iterator<char>(is), std::istreambuf_iterator<char>(), std::back_inserter(v1));

      static const boost::regex namespace_matcher(
         "(?|"
            "(namespace\\s+)boost(_\\w+)?(?:(\\s*::\\s*)phoenix)?"
         "|"
            "(namespace\\s+)(adstl|phoenix|rapidxml)\\>"
         "|"
            "()\\<boost((?:_(?!intrusive_tags)\\w+)?\\s*(?:::))(?:(\\s*)phoenix)?"
         "|"
            "()\\<((?:adstl|phoenix|rapidxml)\\s*(?:::))"
         "|"
         "(namespace\\s+\\w+\\s*=\\s*(?:::\\s*)?)boost(_\\w+)?(?:(\\s*::\\s*)phoenix)?"
//.........这里部分代码省略.........