mostly refactoring operator.h for easier construction of various oper… #1419

Job	Run time
macos-latest: clang++ Release Threads	28m 40s
macos-latest: clang++ Release OneTBB	7m 2s
macos-latest: clang++ Release PaRSEC	3m 31s
ubuntu-20.04: /usr/bin/g++-9 Release Threads	50m 7s
ubuntu-20.04: /usr/bin/g++-9 Release OneTBB	2m 57s
ubuntu-20.04: /usr/bin/g++-9 Release PaRSEC	3m 44s
macos-latest: clang++ Debug Threads	39m 14s
macos-latest: clang++ Debug OneTBB	3m 24s
macos-latest: clang++ Debug PaRSEC	3m 5s
ubuntu-20.04: /usr/bin/g++-9 Debug Threads	57m 37s
ubuntu-20.04: /usr/bin/g++-9 Debug OneTBB	3m 43s
ubuntu-20.04: /usr/bin/g++-9 Debug PaRSEC	3m 13s
	3h 26m 17s

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