draft proposal for Sum Types for D

[Timon Gehr]

On 11/29/22 21:04, Walter Bright wrote:
> On 11/29/2022 9:14 AM, Steven Schveighoffer wrote:
>> On 11/29/22 1:26 AM, Walter Bright wrote:
>>> Go ahead, Make My Day! Destroy!
>>>
>>> https://github.com/WalterBright/DIPs/blob/sumtypes/DIPs/1NNN-(wgb).md
>>
>> In Prior work, I suggest adding 
>> [TaggedAlgebraic](https://github.com/s-ludwig/taggedalgebraic) and I 
>> also suggest reading about how it works. I find it much nicer to use 
>> than std.sumtype.
>>
>> In the DIP, it says that "Member functions of field declarations are 
>> restricted the same way union member functions are." What does this 
>> mean? I can't find any information on this in the spec.
>>
>> An example of what is not allowed would be helpful.
>>
>> -Steve
> 
> I thought it mentioned that copy constructors, postblits, and 
> destructors are not allowed.

When the tag is managed by the language, you know which of those members 
to call under which circumstances, so this seems like an arbitrary 
limitation.