https://issues.dlang.org/show_bug.cgi?id=23969

          Issue ID: 23969
           Summary: TLS in Windows cannot export/import TLS from DLLs
           Product: D
           Version: D2
          Hardware: All
                OS: Windows
            Status: NEW
          Severity: normal
          Priority: P1
         Component: dmd
          Assignee: nobody@puremagic.com
          Reporter: bugzilla@digitalmars.com

The following C code:

    __declspec(dllexport) __declspec(thread) int xxx = 3;

fails to compile with VC with:

    test.c(2): error C2492: 'xxx': data with thread storage duration may not
have dll interface

So it looks like we can't reasonably make that work for D on Windows. The `export` will have to be ignored, because making it an error will make it clumsy to use `export:` attributes.

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