Title Storage から blob を削除する

auto asyncBlock = std::make_unique<XAsyncBlock>();
asyncBlock->queue = queue;
asyncBlock->context = nullptr;
asyncBlock->callback = [](XAsyncBlock* asyncBlock)
{
    std::unique_ptr<XAsyncBlock> asyncBlockPtr{ asyncBlock };    // Take over ownership of XAsyncBlock*.
    HRESULT hr = XAsyncGetStatus(asyncBlock, false);
};

HRESULT hr = XblTitleStorageDeleteBlobAsync(
    xboxLiveContext,
    blobMetadata,
    deleteOnlyIfEtagMatches,
    asyncBlock.get()
);

if (SUCCEEDED(hr))
{
    // The call succeeded, so release the std::unique_ptr ownership
    // of XAsyncBlock* because the callback now takes ownership.
    // If the call fails, std::unique_ptr maintains ownership and deletes XAsyncBlock*.
    asyncBlock.release();
}