Lexicographical object comparison by selected members of a struct

[Ali Çehreli]

On 8/20/21 11:19 PM, Tejas wrote:
> On Saturday, 21 August 2021 at 06:03:33 UTC, Ali Çehreli wrote:
>> On 8/20/21 10:37 PM, Alexandru Ermicioi wrote:
>>> [...]
>>
>> Cool! Much better. :)
>>
>> I could not do
>>
>> [...]
> 
> Did you use that double curly bracket in `static foreach` so that you 
> don't get error for declaring stuff inside `static foreach` ?

Yes. 'static foreach' does not introduce scope, which can be pretty 
useful. For example, one can define functions at module scope.

The subtle differences between 'static foreach' and '(compile-time) 
foreach' can be surprising. For example, I don't understand why I can't use

   foreach (i; 0 .. members.length) {
     enum ident = __traits(identifier, members[i]);
     // ...
   }

Error: variable `i` cannot be read at compile time.

I think it should be. :) members.length is compile-time; so, 'i' should 
be compile time.

And then, why can't 'static foreach' iterate over 'members'?

   static foreach (member; members) {{
     // ...
   }}

Error: value of `this` is not known at compile time

Hm? Well, I am happy that there is always a path through. :)

Ali