将枚举变量转换为枚举类型

Question

I have encountered a code where enum variable is casted to enum type. I am unable to understand the use of such casting. For E. g.

typedef enum{x,y,z} en;

void main(){
  en const v;
  switch(v){
  case (en)y : {
    }
    break;
  case (en)x: {
    }
    break;
  default : {
    foo();
    }
    break;
  }
}

What is the use of casting x or y to enum type that is (en)x in case label?

Answer 1

Such code is symptomatic of sheer paranoia, that's all. In fact, it's possibly harmful since in forcing a cast, you're hinting to the compiler that you know what you're doing so it may not warn you of an errant case label.

switch ing directly on an enum is perfectly valid, as enum s are essentially integral types. You can safely drop the (en) casts.