typeof and bitfields

[Gabriel Dos Reis]

Alexandre Oliva <aoliva@redhat.com> writes:

| On Jan 14, 2005, Gabriel Dos Reis <gdr@integrable-solutions.net> wrote:
| 
| > That is an argument for not returning an int.  It is not an argument
| > for issueing error.  Why not return int_with_2bits?
| 
| Let's see...

Let's see

   typedef int T(int);

    struct A {
       T f;
    };

is A::f a member function, even though it is not declared with the
(member) function notation?

| struct x {
|   unsigned int i:2;
| } *p;
| 
| typedef __typeof(p->i) BF;
| 
| struct y {
|   BF j;
|   BF k:14;
| } *q;
| 
| int main() {
|   __typeof(q->j) m = 7;
| }
| 
| What do you expect to get from this piece of code?

What do you expect from

   int main() {
      struct X {
       unsigned j : 2;
      };

     X x = { 7 };
   }

| Is y::j a bit-field, even though it's not declared with the bit-field
| notation?

Why not?

| Is the declaration of y::k valid?

Why would it be?

|  What is the size of struct y?

we've got an error on k.

|  Do j
| and k pack into a single unsigned int?

we can't pack  things that do not exist.

| Heck, is the declaration of BF valid? 

Yes, why not?

| What if you use BF to declare a global variable, or a function argument?

What if you delcare a global variable or a function parameter like this

    unsigned int x : 2;

?

-- Gaby