D3D12HelloWindow.cpp *(Desktop)

*(Desktop)
Its nice to see these have been sort of recently updated since last I looked at DirectX.
Might I suggest this as a hold over for the ('&' required l-value) until someone gets back at the examples.

template <class T>
constexpr auto& lvalue(T&& value) noexcept {
    return value;
}

void D3D12HelloWindow::PopulateCommandList()
{
    // Command list allocators can only be reset when the associated 
    // command lists have finished execution on the GPU; apps should use 
    // fences to determine GPU execution progress.
    ThrowIfFailed(m_commandAllocator->Reset());

    // However, when ExecuteCommandList() is called on a particular command 
    // list, that command list can then be reset at any time and must be before 
    // re-recording.
    ThrowIfFailed(m_commandList->Reset(m_commandAllocator.Get(), m_pipelineState.Get()));

    // Indicate that the back buffer will be used as a render target.
    m_commandList->ResourceBarrier(1, &lvalue(CD3DX12_RESOURCE_BARRIER::Transition(m_renderTargets[m_frameIndex].Get(), D3D12_RESOURCE_STATE_PRESENT, D3D12_RESOURCE_STATE_RENDER_TARGET)));

    CD3DX12_CPU_DESCRIPTOR_HANDLE rtvHandle(m_rtvHeap->GetCPUDescriptorHandleForHeapStart(), m_frameIndex, m_rtvDescriptorSize);

    // Record commands.
    const float clearColor[] = { 0.0f, 0.2f, 0.4f, 1.0f };
    m_commandList->ClearRenderTargetView(rtvHandle, clearColor, 0, nullptr);

    // Indicate that the back buffer will now be used to present.
    m_commandList->ResourceBarrier(1, &lvalue(CD3DX12_RESOURCE_BARRIER::Transition(m_renderTargets[m_frameIndex].Get(), D3D12_RESOURCE_STATE_RENDER_TARGET, D3D12_RESOURCE_STATE_PRESENT)));

    ThrowIfFailed(m_commandList->Close());
}

Start with D3D12HelloWindow.cpp and inspect PopulateCommandList, especially the two ResourceBarrier calls shown in the issue. Build the D3D12HelloWindow desktop sample to reproduce the required l-value problem; done means the sample compiles with the suggested temporary workaround and the command list still records both barriers correctly.