"Error: `TypeInfo` cannot be used with -betterC" on a CTFE function

[Richard (Rikki) Andrew Cattermole]

On 09/04/2024 12:48 PM, Liam McGillivray wrote:
> On Tuesday, 9 April 2024 at 00:02:02 UTC, Richard (Rikki) Andrew 
> Cattermole wrote:
>> ```d
>> enum Value = (a, b) {
>>     return a + b;
>> }(1, 2);
>> ```
>>
>> This alone should be a CTFE only function.
>>
>> But if we want template parameters, we'd need to wrap it with the 
>> template.
>>
>> ```d
>> template Value(int a, int b) {
>>     enum Value = () {
>>         return a + b;
>>     }();
>> }
>>
>> int value = Value!(1, 2);
>> ```
>>
>> Does that help?
> 
> I had to reread this a few times to get a sense of what this is. I might 
> have just got it. This is effectively a CTFE function for generating a 
> constant based on the sum of two numbers, right? Doing `int value = 
> Value!(1, 2);` would set `value` to 3, right?

Yes.

> I suppose this was a good new thing to learn, though I'm still quite far 
> from being able to construct a function from another function using a 
> template.
> 
> I suppose that if I wanted it to make a function from another function, 
> I may be able to do it in a template using some `static foreach` to make 
> arrays of function parameters, and then combine them together without 
> the use of strings, instead using placeholders (aliases or whatever 
> they'd be called) and maybe the `tupleof` function. Am I headed in the 
> right direction (if you can understand my weak attempt to describe the 
> direction I'm thinking of going in)?

``tupleof`` isn't a function, its a property to get a "tuple" a sequence 
of fields for a struct/class.

However most likely you'd have to resort to string mixins if you're 
messing about with parameters like I think? you are asking for.

I'm not entirely sure what you're wanting there.