Move get_normal to Offset::normal (issue 576000043 by address@hidden)

[dak]

https://codereview.appspot.com/576000043/diff/577750046/flower/include/offset.hh
File flower/include/offset.hh (right):

https://codereview.appspot.com/576000043/diff/577750046/flower/include/offset.hh#newcode123
flower/include/offset.hh:123: Offset normal() const {
It's kind of unusual to make a constructing function a (non-static)
member function unless this is necessitated for operator semantics,
because different conversion rules apply and there is some expectation
that member functions delivering the class type may change stuff
in-place (the const is not seen at call sites).

Any reason to depart from conventions here?

https://codereview.appspot.com/576000043/