Basic operator API #601

Job	Run time
Rustfmt	24s
coverage	8m 5s
clippy	2m 15s
Check	2m 23s
Test Suite (ubuntu-20.04, stable)	8m 3s
Test Suite (self-hosted, linux, arm64, --cfg=aes_armv8, nightly-2023-06-27)	6m 53s
Test Suite (self-hosted, macos, arm64, --cfg=aes_armv8, nightly-2023-06-27)	2m 34s
Test Suite (macos-latest, stable)	10m 6s
Test Suite (windows-2019, stable)	7m 49s
Build library (ubuntu-20.04, libpost.so, libpost.a, linux, stable)	4m 6s
Build library (self-hosted, linux, arm64, libpost.so, libpost.a, --cfg=aes_armv8, linux-arm64, ni...	5m 49s
Build library (self-hosted, macos, arm64, libpost.dylib, libpost.a, --cfg=aes_armv8, macos-m1, ni...	2m 43s
Build library (macos-latest, libpost.dylib, libpost.a, macos, stable)	9m 43s
Build library (windows-2019, post.dll, post.lib, windows, stable)	13m 43s
Publish release	0s
	1h 24m 36s

Provide feedback