View Compilation Error

0_0_25645906_25284.cpp
0_0_25645906_25284.cpp(6) : error C2668: “log2”: 对重载函数的调用不明确
        VC2013\INCLUDE\math.h(1215): 可能是“long double log2(long double) throw()”
        VC2013\INCLUDE\math.h(1099): 或       “float log2(float) throw()”
        VC2013\INCLUDE\math.h(504): 或       “double log2(double)”
        尝试匹配参数列表“(int)”时
0_0_25645906_25284.cpp(15) : fatal error C1071: 在注释中遇到意外的文件结束