Regarding typedefs of 1-element arrays in C

Question

Sometimes, in C, you do this:

typedef struct foo {
   unsigned int some_data;
} foo; /* btw, foo_t is discouraged */
         


        

Answer 1

The only advantage to this method is nicer looking code and easier typing. It allows the user to create the struct on the stack without dynamic allocation like so:

foo bar;

However, the structure can still be passed to functions that require a pointer type, without requiring the user to convert to a pointer with &bar every time.

foo_init(bar);

Without the 1 element array, it would require either an alloc function as you mentioned, or constant & usage.

foo_init(&bar);

The only pitfall I can think of is the normal concerns associated with direct stack allocation. If this in a library used by other code, updates to the struct may break client code in the future, which would not happen when using an alloc free pair.