https://issues.dlang.org/show_bug.cgi?id=21219

          Issue ID: 21219
           Summary: Invalid C++ header generated for extern(C++,
                    [class|struct])
           Product: D
           Version: D2
          Hardware: All
                OS: All
            Status: NEW
          Severity: normal
          Priority: P1
         Component: dmd
          Assignee: nobody@puremagic.com
          Reporter: moonlightsentinel@disroot.org

Example:

===============================================
extern(C++, class) struct ClassFromStruct {}

extern(C++, class) class ClassFromClass {}

extern(C++, struct) struct StructFromStruct {}

extern(C++, struct) class StructFromClass {}
===============================================


dmd  -c -o- -HC missing_class.d
===============================================
// Automatically generated by Digital Mars D Compiler v2092

#pragma once

#include <stddef.h>
#include <stdint.h>


// ignoring non-cpp struct ClassFromStruct because of linkage
class ClassFromClass
{
public:
};

// ignoring non-cpp struct StructFromStruct because of linkage
class StructFromClass
{
public:
};
===============================================

There are mutliple issues here:

- ClassFromStruct and StructFromStruct are missing
- StructFromClass is declared as class.

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