Use default copy constructors and assignment operators where possible

9 jobs for v2.1rc2 in 11 minutes and 8 seconds (queued for 3 seconds)
Status Job ID Name Coverage
  Test
passed #94983
VS2015
VS2015-32-bit

00:01:20

passed #94982
VS2015
VS2015-64-bit

00:01:30

passed #94981
VS2017
VS2017-32-bit

00:01:31

passed #94980
VS2015
VS2017-64-bit

00:01:38

passed #94977
Linux
clang-c++11

00:02:58

passed #94979
Linux
cppcheck

00:03:50

passed #94984
Linux
doc

00:00:05

passed #94976
Linux
gcc-c++11

00:05:30

passed #94978
Apple
macos-c++11

00:01:48