View Compilation Error

779993_0_0_15347.cpp
779993_0_0_15347.cpp(139) : error C2475: “std::basic_string<_Elem,_Traits,_Ax>::length” : 构造一个指向成员的指针需要显式使用 address-of 运算符('&')和限定名
        with
        [
            _Elem=char,
            _Traits=std::char_traits<char>,
            _Ax=std::allocator<char>
        ]
779993_0_0_15347.cpp(139) : error C2475: “std::basic_string<_Elem,_Traits,_Ax>::length” : 构造一个指向成员的指针需要显式使用 address-of 运算符('&')和限定名
        with
        [
            _Elem=char,
            _Traits=std::char_traits<char>,
            _Ax=std::allocator<char>
        ]
779993_0_0_15347.cpp(139) : error C2446: “<” : 没有从“std::basic_string<_Elem,_Traits,_Ax>::size_type (__thiscall std::basic_string<_Elem,_Traits,_Ax>::* )(void) const”到“int”的转换
        with
        [
            _Elem=char,
            _Traits=std::char_traits<char>,
            _Ax=std::allocator<char>
        ]
        没有使该转换得以执行的上下文
779993_0_0_15347.cpp(139) : error C2297: “<” : 非法，右操作数包含“std::basic_string<_Elem,_Traits,_Ax>::size_type (__thiscall std::basic_string<_Elem,_Traits,_Ax>::* )(void) const”类型
        with
        [
            _Elem=char,
            _Traits=std::char_traits<char>,
            _Ax=std::allocator<char>
        ]