• user1234 (19/19) May 16 Given
• Steven Schveighoffer (16/35) May 17 `__gshared` is a storage class. It means, store this thing in the

user1234 <user1234 12.de> writes:

Given

```d
struct S
{
     int member;
}

__gshared S s;
```

It's clear that `s.member` is `__gshared` too, right ?
What does happen for

```d
struct S
{
     int member;
     static int globalMember;
}

__gshared S s;
```

Is then `S.globalMember` a TLS variable ? (I'd expect that)

Steven Schveighoffer <schveiguy gmail.com> writes:

On Thursday, 16 May 2024 at 17:04:09 UTC, user1234 wrote:
 Given

 ```d
 struct S
 {
     int member;
 }

 __gshared S s;
 ```

 It's clear that `s.member` is `__gshared` too, right ?
 What does happen for

 ```d
 struct S
 {
     int member;
     static int globalMember;
 }

 __gshared S s;
 ```

 Is then `S.globalMember` a TLS variable ? (I'd expect that)

`__gshared` is a storage class. It means, store this thing in the 
global memory segment. `static` storage class means store this 
thing in TLS.

Storage classes are *not* transitive, and they are not type 
constructors. They optionally might apply a type constructor to 
the type (such as the `const` storage class), but not always.

So in this case `typeof(s)` is `S`, not `__gshared S`. `s.member` 
is in the global segment since structs members are placed within 
the struct memory location (in this case, the global memory 
segment).

`globalMember` is placed in TLS because it's storage class is 
`static`, and `static` means, do not store with the instance 
(which for `s` would mean the global memory segment), but rather 
in TLS.

-Steve