我如何以编程方式将IAsyncOperation强制为错误状态？

Question

我有一些C ++ / WinRT代码，它们异步返回一个字符串。但是，某些内部操作可能会失败，而当这样做时，我需要使IAsyncOperation也移到错误状态。 co_return显然将操作移至完成状态；如何将操作移至错误状态？精简的代码如下：

winrt::IAsyncOperation<winrt::hstring> MyClass::DoAuthenticationAsync()
{
    auto acctProvider = co_await winrt::WebAuthenticationCoreManager::FindAccountProviderAsync(AccountProviderId, authority, user);
    auto webToken = winrt::WebTokenRequest(acctProvider, CarbonScope, CarbonClientId, winrt::WebTokenRequestPromptType::Default);

    webToken.Properties().Insert(L"authority", authority);
    webToken.Properties().Insert(L"resource", resource);

    auto requestResult = co_await winrt::WebAuthenticationCoreManager::GetTokenSilentlyAsync(webToken);

    auto requestStatus = requestResult.ResponseStatus();
    if (requestStatus == winrt::WebTokenRequestStatus::Success)
    {
        co_return requestResult.ResponseData().GetAt(0).Token();
    }
    else if (requestStatus == winrt::WebTokenRequestStatus::UserInteractionRequired)
    {
        auto uxresult = co_await winrt::WebAuthenticationCoreManager::RequestTokenAsync(webToken);

        requestStatus = uxresult.ResponseStatus();
        if (requestStatus == winrt::WebTokenRequestStatus::Success)
        {
            co_return uxresult.ResponseData().GetAt(0).Token();
        }
    }
    if (requestStatus == winrt::WebTokenRequestStatus::ProviderError)
    {
        // here I'd like to have the IAsyncOperation have an Error status with the ErrorCode from the requestResult.
        auto err = requestResult.ResponseError().ErrorCode();
    }
    co_return L"";
}