Using onOutOfMemoryError in C wrappers

[Per Nordlöw]

On Wednesday, 24 March 2021 at 08:31:19 UTC, Basile B. wrote:
> There are several ways to do that. In addition to 
> onOutOfMemoryError, you can use a static instance
>
>   void v() @nogc nothrow
>   {
>     __gshared oom = new OutOfMemoryError();
>     auto X* = X_create();
>     if (X is null)
>         throw oom;
>   }

How is that better than

     void v() @nogc nothrow
     {
         auto X* = X_create();
         if (X is null)
             onOutOfMemoryError();
     }

considering the fact that accessing `__gshared` state is neither 
`@safe` nor `pure`? Which, in turn, makes `v()` unconditionally 
unsafe and unpure regardless of safety and purity of `X_create()`.