Question

Declaring a struct with typedef

typedef struct some_struct {
int someValue;
} *pSomeStruct;

and then passing it as a parameter to some function with const declaration, implying ‘const some_struct * var’

void someFunction1( const pSomeStruct var )

turns out to become

some_struct * const var

This is also stated in Section 6.7.5.1 of the ISO C standard which states that ‘const’ in this case applies to the pointer and not to the data to which it points.

So the question is – is there a way to declare a pointer to a const struct in a shorthanded notation with typedef, or there must always be a special separate declaration for it:

typedef const struct some_struct *pcSomeStruct;
void someFunction2( pcSomeStruct var )

Answer 1

Basically, do not typedef pointers 🙂

typedef struct some_struct {} some_struct;

void some_function1(some_struct *var);
void some_function2(const some_struct *var);
void some_function3(some_struct *const var);
void some_function4(const some_struct *const var);

---

Or, don’t typedef at all 😀

struct some_struct {};

void some_function1(struct some_struct *var);
void some_function2(const struct some_struct *var);
void some_function3(struct some_struct *const var);
void some_function4(const struct some_struct *const var);