Is this a memory leak in slate API?

I am writing plugins for Unreal Engine 4 and I have noticed something strange about using widget Slots. for example when you write


+ SHorizontalBox::Slot()

this is being called



static FSlot& Slot()
{
    return *(new FSlot());
}


can you find where this pointer is deleted? I could find nothing. the + operator for adding slots is given to you by this macro



SLATE_BEGIN_ARGS(SHorizontalBox)
...
SLATE_SUPPORTS_SLOT(SHorizontalBox::FSlot)
...
SLATE_END_ARGS(SHorizontalBox)


which becomes



TArray< SHorizontalBox::FSlot* > Slots;
WidgetArgsType& operator + (SHorizontalBox::FSlot& SlotToAdd)
{
    Slots.Add( &SlotToAdd );
    return *this;
}


and that’s all there is.

Now I’m wondering when this slot object allocated on heap is destroyed? does TArray automatically delete pointers? how?