[Feature request] Wrappers for common types, e.g. BSTR, VARIANT, SAFEARRAY

[heaths]

While winapi exposes many of these types of functions necessary to use them, there isn't any good support for these types often used in COM. For example, I wrote a BStr (though, I suppose that should be BString to match the Rust naming convention) that exposes just enough of what I need, but this could be expanded considerably to implement From traits and more, and be readily available for use with the com crate. Same for VARIANT and even SAFEARRAY.

[MarijnS95]

If helpful at all, we do a similar thing in hassle-rs (a potential future user of com-rs):

https://github.com/Traverse-Research/hassle-rs/blob/ms-com-rs/src/os.rs
https://github.com/Traverse-Research/hassle-rs/blob/ms-com-rs/src/utils.rs

We'd be happy if these can be moved to a (Windows common) crate as long as types and wrappers are exposed for Linux.

[rylev]

We're working on a solution for this that we hope to be able to share shortly. Stay tuned!

[Bigous]

Does this old crate can help?

Or, is there any news? I'm stuck on the IRtdServer interface, that has this idl with SAFEARRAY(VARIANT)* and IRTDUpdateEvent* as parameter:

// TLib :     // TLib : OLE Automation : {00020430-0000-0000-C000-000000000046}
importlib("stdole2.tlb");

// Forward declare all types defined in this typelib
interface IScripRTD;
interface IRTDUpdateEvent;

[
  uuid(A04A3240-D051-4B4C-B004-CA92151F11E5),
  helpstring("ScripRTD Class")
]
coclass ScripRTD {
    [default] interface IScripRTD;
};

[
  odl,
  uuid(EC0E6191-DB51-11D3-8F3E-00C04F3651B8),
  helpstring("IScripRTD Interface"),
  dual,
  nonextensible,
  oleautomation
]
interface IScripRTD : IDispatch {
    [id(0x0000000a)]
    HRESULT ServerStart(
                    [in] IRTDUpdateEvent* callback, 
                    [out, retval] long* result);
    [id(0x0000000b)]
    HRESULT ConnectData(
                    [in] long topicId, 
                    [in] SAFEARRAY(VARIANT)* strings, 
                    [in, out] VARIANT_BOOL* newValues, 
                    [out, retval] VARIANT* values);
    [id(0x0000000c)]
    HRESULT RefreshData(
                    [in, out] long* topicCount, 
                    [out, retval] SAFEARRAY(VARIANT)* data);
    [id(0x0000000d)]
    HRESULT DisconnectData([in] long topicId);
    [id(0x0000000e)]
    HRESULT Heartbeat([out, retval] long* result);
    [id(0x0000000f)]
    HRESULT ServerTerminate();
};

[
  odl,
  uuid(A43788C1-D91B-11D3-8F39-00C04F3651B8),
  dual,
  oleautomation
]
interface IRTDUpdateEvent : IDispatch {
    [id(0x0000000a)]
    HRESULT UpdateNotify();
    [id(0x0000000b), propget]
    HRESULT HeartbeatInterval([out, retval] long* value);
    [id(0x0000000b), propput]
    HRESULT HeartbeatInterval([in] long value);
    [id(0x0000000c)]
    HRESULT Disconnect();
};