If Tools/Options.../C++/Clangd option is On we have next trouble:
For functions which return type is: either reference, rvalue reference or pointer, — it's declarations does not correctly appears in the top and right side editor's panes! (see attached screenshots)

To avoid this problem I use C++ keyword "using" to define type alias:
template<typename T> using Pointer = T *;
template<typename T> using Reference = T&;

After that I have correct function outlines! (see attached screenshots)