Source of CPlusPlus17

TITLE:C++17
[[C++>CPlusPlus]] > [[C++0xCPlusPlus17]]

- C++17の新機能予定
--   http://faithandbrave.hateblo.jp/entry/2014/11/25/145617

* Boost [#ibb9c48b]

- How C++17 Benefits from the Boost Libraries
--  https://www.bfilipek.com/2019/12/bosttocpp17.html