View Compilation Error

0_0_12821301_18107.cpp
0_0_12821301_18107.cpp(25) : error C2039: “pop_back” : 不是“std::basic_string<_Elem,_Traits,_Ax>”的成员
        with
        [
            _Elem=char,
            _Traits=std::char_traits<char>,
            _Ax=std::allocator<char>
        ]
0_0_12821301_18107.cpp(31) : error C2039: “pop_back” : 不是“std::basic_string<_Elem,_Traits,_Ax>”的成员
        with
        [
            _Elem=char,
            _Traits=std::char_traits<char>,
            _Ax=std::allocator<char>
        ]
0_0_12821301_18107.cpp(40) : error C2039: “pop_back” : 不是“std::basic_string<_Elem,_Traits,_Ax>”的成员
        with
        [
            _Elem=char,
            _Traits=std::char_traits<char>,
            _Ax=std::allocator<char>
        ]
0_0_12821301_18107.cpp(42) : error C2039: “pop_back” : 不是“std::basic_string<_Elem,_Traits,_Ax>”的成员
        with
        [
            _Elem=char,
            _Traits=std::char_traits<char>,
            _Ax=std::allocator<char>
        ]
0_0_12821301_18107.cpp(52) : error C2039: “pop_back” : 不是“std::basic_string<_Elem,_Traits,_Ax>”的成员
        with
        [
            _Elem=char,
            _Traits=std::char_traits<char>,
            _Ax=std::allocator<char>
        ]
0_0_12821301_18107.cpp(52) : error C2039: “pop_back” : 不是“std::basic_string<_Elem,_Traits,_Ax>”的成员
        with
        [
            _Elem=char,
            _Traits=std::char_traits<char>,
            _Ax=std::allocator<char>
        ]