Replace fwd-declaration.
Merge topic 'fix-Qt-autogen' into next

c38daaf2 Replace fwd-declaration.
Extend set insert non-use doc.
Merge topic 'disallowed-cxx-subset' into next

d1a3e809 Extend set insert non-use doc.
Algorithm -> loop.
Merge topic 'fix-Qt-autogen' into next

1b6d0f73 Algorithm -> loop.