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0_0_11248431_968.cpp
0_0_11248431_968.cpp(47) : error C2039: “front” : 不是“std::basic_string<_Elem,_Traits,_Ax>”的成员
        with
        [
            _Elem=char,
            _Traits=std::char_traits<char>,
            _Ax=std::allocator<char>
        ]