Using an anonymous struct vs a named struct with typedef

Question

When should one of the following statements be used over the other?

typedef struct Foo {
    int a;
} Bar;

and

typedef stru         


        

Answer 1

When creating an opaque data type which is when the header only contains a forward declaration of the struct and the actual definition of it's members is in the source file. Since you cannot forward declare a typedef you'll have to give a struct a name. Example:

Foo.h

typedef struct Foo_ Foo;

Foo.c

struct Foo_ {
    int a;
};

Also when you have a recursive data structure such as linked list which everyone else has mentioned.