fat struct style guide?

[H. S. Teoh]

On Tue, Feb 24, 2026 at 04:21:01PM +0000, monkyyy via Digitalmars-d-learn wrote:
> On Tuesday, 24 February 2026 at 16:19:05 UTC, H. S. Teoh wrote:
> > On Tue, Feb 24, 2026 at 03:56:20PM +0000, monkyyy via
> > Digitalmars-d-learn wrote:
> > > On Tuesday, 24 February 2026 at 15:30:39 UTC, H. S. Teoh wrote:
[...]
> > > > > What's a "fat struct"?
> > [...]
> > > Something like a "entity" that has a first member is a id allowing
> > > for intrusive sumtypes from void* pointers or a giant union and
> > > just allot of data.
> > [...]
> > 
> > So is that like ECS or something along those lines?
[...]
> Related ideas, but ecs will definitely have components which is a
> whole thing of complexity and makes for scheduling and you start
> talking about custom compilers.
> 
> All good ecs will probably be fat structs, but components are not
> necessarily members of good entities.

Hmm.  So basically the idea is to stuff everything into a single struct
so that you keep everything in cache instead of having to dereference
pointers?

Sounds like something you could use compile-time introspection for.  Say
you have some kind of compile-time spec of what sub-structs go into some
entity, then have compile-time code auto-generate the fat struct that
contains everything in these sub-structs.  Could do it in a way that
makes it easy to change at the code level without editing tons of struct
definitions (by using CTFE to generate said definitions and then mix
them in).


T

-- 
"If this is the solution, I want my precipitate back."