How to typecast enum to union in C

Question

Hello, I am working on the embedded C and I need to typecast enum to union. I tried doing it constant cast but it is showing error.

Answer 1

As far as I understand it your external hardware has its outputs at address (pin?) 1, 2, 3 and 4 while your other hardware has it at 0, 1, 2 and 3?

If you use an enum the default value is 0, but you can set the first value to 1 to have the next value be 2, then 3, etc. ( or you can explicitly set each enum value )

typedef enum
{
A = 1,
B,
C,
D
} E;

Sorry if I didn't understand correctly.

Answer 2

Not sure what you mean. What's wrong with something like

typedef enum
{
A, B, C, D
} E;

typedef union
{
E e;
} U;

int main()
{
U u = { .e = B };
}

Answer 3

Okay Thanks I didn't no we can explicitly set the value of enum. Thanks

Answer 4

Just curious ...
What benefit is gained from this, if it was even possible?
Aren't they two different things and purpose?

Answer 5

I am having 2 Hardware that needs to be interfaced with microcontroller. So for that i need both

Answer 6

Dennis
Advise please?

Answer 7

Let me explain in detail. My external hardware has 4 output whose address start with 1 and other hardware has its address start from 0. So for the second hardware I used enum as it gave me values from 0 to 4 but now I cannot use it for 2nd hardware as the address location of each pin needs to be matched.
So If i can typecast enum to union then i can define the var as per my need

Answer 8

Or if there is any other way to do it