c - ANSI C 中是否定义了枚举加法？

Question

是否保证此代码后的state为LX_DONE？

enum lx_state { LX_START, LX_MIDDLE, LX_DONE };

enum lx_state state = LX_START;
++state;
++state;

Answer 1

是的，C 标准说，在 6.7.2.2/3 中，

Each subsequent enumerator with no = defines its enumeration constant as the value of the constant expression obtained by adding 1 to the value of the previous enumeration constant