On Wednesday, 21 May 2025 at 04:44:35 UTC, Walter Bright wrote:
> 1. use `size_t` for all indices and pointer offsets
>
> 2. use `ptrdiff_t` for all deltas of the form `size_t - size_t`

Thanks for that advice!

> [...]
> You could also do this:
> ```d
> foreach_reverse(ptrdiff_t i, v; messages) // messages is a string array
> {
>     float vpos = 600 - 30 * i;
>     DrawText(messages.ptr, 100, vpos.to!int, 20, Colors.WHITE);
> }
> ```
> but one could argue it's a bit too clever.

Looks okay. Or is the `reverse` part of the cleverness? I mean the
ordinary (forward) foreach also seem to work.

In my not-so-humble opinion, every cast is a bug, as it breaks the type system.

I posted an example that showed how this particular problem can be dealt with without casting.

On 5/21/2025 12:24 PM, Derek Fawcus wrote:
> "After much discussion, the Committee decided in favor of value preserving rules, despite the fact that the UNIX C compilers had evolved in the direction of unsigned preserving."

At that time, 90% of C programming was done on DOS, not Unix. And there were a lot of value preserving compilers.

On Wednesday, 21 May 2025 at 20:53:13 UTC, Walter Bright wrote:
> every cast is a bug,

How do you make fast inverse sqrt, sumtypes, allocators?

On 5/21/2025 12:43 PM, kdevel wrote:
> On Wednesday, 21 May 2025 at 04:44:35 UTC, Walter Bright wrote:
>> but one could argue it's a bit too clever.
> 
> Looks okay. Or is the `reverse` part of the cleverness? I mean the
> ordinary (forward) foreach also seem to work.

It's "clever" because it isn't clear why it is structured this way.

On 5/21/2025 3:00 PM, monkyyy wrote:
> On Wednesday, 21 May 2025 at 20:53:13 UTC, Walter Bright wrote:
>> every cast is a bug,
> 
> How do you make fast inverse sqrt, sumtypes, allocators?

You call it @system code!

On 5/21/2025 6:27 PM, Steven Schveighoffer wrote:
> It's so clever, in fact, that it doesn't work. I'll let you discover why.

LOL, you're right. While the types are correct, the wrap around still makes it wrong.

BTW, if you typed everything but the float as `int`, you still have the same problem. It's not the unsigned conversion that is wrong.