Passing integer to a function that has enum as input parameter

Question

I've got a question

What shall happen if we have the following :

typedef enum  {s1=0,s2,s3} states ;

void test( states x ) ;

when using the function test , what happens if I use it like the following :

test(6);

Shall it be mapped to the nearest enum value , or it needs to be handled in the function implementation ?

Answer 1

enum are effectively treated as int by most C compilers. They are just syntactic sugar to make code more readable. In your case, 6 will be passed to the function and the function has to handle it.

Answer 2

[for C]

If doing

test(6);

6 will be passed to test() (as enums are (treated as) ints) and it shall be trapped by the function's input validation.

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Update:

Input validation is not done automagically. It needs to be coded explicitly.