Initialization of struct containing anonymous union

[Steven Schveighoffer via Digitalmars-d-learn]

On 8/14/17 10:36 AM, Carl Sturtivant wrote:
> On Monday, 14 August 2017 at 14:24:40 UTC, Steven Schveighoffer wrote:
>>
>> I think what the docs mean is that as soon as an anonymous union is 
>> present, you can't initialize anything further than the first union 
>> field.
> 
> I understood that, hence my remark that "this is not helpful".

OK. I thought you meant that the documentation is not helpful enough to 
understand what it means.

> 
>>> So it seems I am forced to assign explicitly to each member of the 
>>> struct, an ugly process.
>>>
>>> What is a nice way to solve this problem?
>>
>> I think the only way to solve it is with a constructor:
>>
>> this(int ival, double xval) { i = ival; x = xval; }
> 
> As I though I made clear, I don't want write assignments to each 
> variable in a 50 or 100 member struct from a library when D could supply 
> a better solution.

Sorry, I thought you meant to assign the fields manually outside an 
initializer function.

> I can print out such a struct using writeln, but can 
> find no way to use that text cleaned up in source code to create such a 
> struct. Is D completely deficient here?

Hm... have you tried named field initializers?

mess m = { i: 99, x: 3.14};

Seems to work for me.

I believe you could generate a constructor given the introspection of 
the fields themselves. Probably would be messy though.

-Steve