Is this a memory leak in slate API?

[KazemAkhgary]

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?