winrt_server.cpp

#include <Unknwn.h>
#include <winrt/Windows.Foundation.h>

using namespace winrt;
using namespace Windows::Foundation;

struct Stringable : implements<Stringable, IStringable>
{
    hstring ToString()
    {
        return L"Hello from server";
    }
};

struct Factory : implements<Factory, IClassFactory>
{
    HRESULT __stdcall CreateInstance(
        IUnknown* outer,
        GUID const& iid,
        void** result) noexcept final
    {
        *result = nullptr;

        if (outer)
        {
            return CLASS_E_NOAGGREGATION;
        }

        return make<Stringable>().as(iid, result);
    }

    HRESULT __stdcall LockServer(BOOL) noexcept final
    {
        return S_OK;
    }
};

static constexpr GUID server_clsid // DAA16D7F-EF66-4FC9-B6F2-3E5B6D924576
{
    0xdaa16d7f, 0xef66, 0x4fc9, { 0xb6, 0xf2, 0x3e, 0x5b, 0x6d, 0x92, 0x45, 0x76 }
};

int main()
{
    init_apartment();
    
    DWORD registration{};

    check_hresult(CoRegisterClassObject(
        server_clsid,
        make<Factory>().get(),
        CLSCTX_LOCAL_SERVER,
        REGCLS_SINGLEUSE,
        &registration));

    puts("Press Enter me when you're done serving.");
    getchar();
}