Avoid booleans as struct fields

[erlingrj]

Good feedback from Edward. A boolean as a struct field wastes 31 bits. I think we can use C's ability to specify bitwidths as follows

struct MyStruct {
  bool first: 1;
  bool second: 1;
  int small_int:6
  int bigger_int:8
  int biggest_int:16
};

This should all fit in one 32bit word

[edwardalee]

I don't think you can assume the compiler will put these in a 32-bit word. What I had in mind was more like this:

struct my_struct_t {
   int32_t flags;
   ...
}

Then have macros like FIRST(struct) and SECOND(struct) that you use in conditionals.

[erlingrj]

Then what is the meaning of int a:4? I thought it was exactly for this purpose?

[edwardalee]

Oh, I don't know. I'm not familiar with that syntax.