927588_0_0_13494.cpp 927588_0_0_13494.cpp(9) : error C2065: “a” : 未声明的标识符 927588_0_0_13494.cpp(9) : error C2065: “b” : 未声明的标识符 927588_0_0_13494.cpp(9) : error C2617: “f” : 返回语句不一致 927588_0_0_13494.cpp(2) : 参见“f”的声明