无法绑定＆＃39; std :: basic_istream <char>＆＃39;左值＆＃39; std :: basic_istream <char>＆amp;＆amp;＆＃39; </char> </char>

Question

我有这个c ++代码片段在visual studio中工作正常但在gcc中出错。欢迎任何有关如何使其工作的建议？

  template <typename ConvertType>

  inline bool Parse(const std::string& input, ConvertType& output)
  {
    std::stringstream stream(input);
    stream.imbue(std::locale::classic());
    return (stream >> output) != NULL;      
  }

我收到此错误：

./Configuration/Option.h:32:38: error: cannot bind 'std::basic_istream' lvalue to 'std::basic_istream&&'
/usr/include/c++/4.6/istream:852:5: error:   initializing argument 1 of 'std::basic_istream& std::operator>>(std::basic_istream&&, _Tp&) [with _CharT = char, _Traits = std::char_traits, _Tp = Color]'

Answer 1

(stream >> output)返回对流的引用，无法与NULL进行比较。你可以简单地返回

return (stream >> output);

将通过调用operator void*() const（C ++ 11中的explicit operator bool() const）来测试流，该fail()调用{{1}}函数来测试操作是否成功。