因为C标准并没有规定字符串字面值的类型就是const char*
标准只是说了
In translation phase 7, a byte or code of value zero is appended to each multibyte
character sequence that results from a string literal or literals.65) The multibyte character sequence is then used to initialize an array of static storage duration and length just sufficient to contain the sequence. For character string literals, the array elements have type char。
但是你记住字符串字面量现在就是const char*就是了。