如何为枚举变量赋予枚举

Question

I have the following code in C:

typedef enum
{
   MONDAY = 0,
   TUESDAY,
   WEDNESDAY
} Weekday;

typedef struct
{
   int age;
   int number;
   Weekday weekday;
} Info;

typedef struct
{
   int age;
   Weekday weekday;
} Data;

Info info;
Data data;
info.weekday = data.weekday;

The lint gives the following error:

info.weekday = data.weekday; Type mismatch (assignment) (enum/enum)

how to assign a enum to another enum variable?

Answer 1

Replace the semicolon with a comma here :

MONDAY = 0;

If there's still an error, you need to show more code.

Edit : My fault, didn't know "lint".

It seems that lint is a bit too paranoid. That kind of assignment could not possibly go wrong. So as AnthonyLambert said, just disable this error (or don't use lint ?).

One last trick I can think of, but I wouldn't bet on it, is to name your enum :

typedef enum Weekday
{
    //...
} Weekday;

The last option you have, which I don't recommend either, is to use int in your structures :

typedef struct
{
    // ...
    int weekday;
} Info;

Then you can assign enumerators to these variables.

Answer 2

Your code is not incorrect, it's just lint pointing out a potential error. this error would not show up if compiled with a C++ compiler where it retains the type info.

The problem is that in C as soon as you assign a enum value it becomes an int type. So as soon as you read from Weekday its type is now int not Weekday.

The way to get round the error being reported in lint by coding would be to force it to assign from the enum again like so.

void SetWeekday( Info *info, Data* data )
{
     switch (Data->Weekday)
     {
         case MONDAY: info->Weekday = MONDAY;
         case TUESDAY: info->Weekday = TUESDAY;
         etc...
     }
}

Alternatively lint allows you to disable each error individually, would is probably best.

( This code has not been compiled and may contain nuts and/or small insects. etc... )