Wondering why the double "!!" in this api. The same !! is in SetAutoApplyNewWindows/Threads. Guessing the compiler optimizes it away.

void CXTPSkinManager::Suspend()
{
    _ASSERTE("Already suspended" && !IsSuspended());
    if (IsSuspended())
        return;

    m_SuspendedState.u.bSuspended         = TRUE;
    m_SuspendedState.u.bAutoApplyWindows = !!m_bAutoApplyWindows;
    m_SuspendedState.u.bAutoApplyThreads = !!m_bAutoApplyThreads;
    m_SuspendedState.u.bApplyDCs         = !!HasApplyOptions(xtpSkinApplyDCs);

    SetAutoApplyNewWindows(FALSE);
    SetAutoApplyNewThreads(FALSE);
    ModifyApplyOptions(0, xtpSkinApplyDCs);
}