Member variables in method are null when called as delegate from thread

[Paul Backus]

On Monday, 11 January 2021 at 16:10:49 UTC, Steven Schveighoffer 
wrote:
> There are some... odd rules.
>
> struct S
> {
[...]
>    immutable int e = 5; // stored in data segment, not per 
> instance!

Are you sure?

struct S
{
     immutable int n = 123;
     this(int n) { this.n = n; }
}

void main()
{
     S s1;
     S s2 = 456;
     assert(s1.n == 123);
     assert(s2.n == 456);
}