clangd-9 1:9.0.1-12 (armhf binary) in ubuntu focal

 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.