clangd-9 1:9-2~ubuntu18.04.1 (s390x binary) in ubuntu bionic

 clangd understands your C++ code and adds smart features to your editor:
  - code completion
  - compile errors
  - go-to-definition
  - and more.
 .
 clangd is a language server that implements the Language Server Protocol;
 it can work with many editors through a plugin.