[Cs3] maps and emplace()

[Mikhail Nesterenko]

CS3 stdudents,

Emplace with maps is and is not straightforward. I came up with
example usage here:

   http://antares.cs.kent.edu/~mikhail/classes/cs3/Examples/STLContainersAssociative/mapEmplace.cpp

Some experts (Scott Meyers) endorse emplace() for efficiency, others
(Bjarne Stroustrup) oppose due to safety concerns. C++11 makes certain
efficient things with emplace() rather wordy and it is updated in
C++17 with, what looks to me, even more wordiness.

Here is a detailed discussion on that:

  https://www.fluentcpp.com/2018/12/11/overview-of-std-map-insertion-emplacement-methods-in-cpp17/

Thanks,
-- 
Mikhail