Default struct constructor

[bitwise]

On Friday, 8 February 2019 at 19:24:00 UTC, Victor Porton wrote:
> On Friday, 8 February 2019 at 19:20:59 UTC, psycha0s wrote:
>> What kind of problems a default struct constructor could 
>> solve? If you want to use RAII, you need to pass the resource 
>> as an argument. If you want to set some initial state, you can 
>> do it by assigning values to the struct members directly.
>
> In my particular case I need RAII initializing a C library 
> object. Some of the C constructor functions don't have 
> arguments. So the only way to do it is my silly hack with Dummy 
> object. I would probably vote for a change in D spec.

I've boiled my requirement down to structs having a "lifetime 
starting" method of some kind. I don't mind if T.init is blitted 
over my object before it's called, as long as I can initialize 
any struct fields that couldn't be initialized inline due to 
their value not being CTFE'able.

I suppose that for this to be worth doing though, it would need 
to work extern(D) as well. So creating the object in D would blit 
T.init to the struct first, while creating the same object in C 
would not. So I'm wondering if this difference would be a deal 
breaker (I don't believe it should be), or if what I'm suggesting 
creates other technical problems (I can't think of any).