I am using neovim for a while now and lately coding a bit more in C++.
When I use a function in the code that I realize I haven't yet declared/defined clangd gives the typical Use of undeclared identifier ... error in nvim. However I'd like to know whether there is a plugin or smth builtin that provides a quick fix for this. I.e. as I already typed out the name of the (still missing) function that then auto generates the declaration and definition in the header and cpp file. I know that depends a bit on context what is typically desirable, but often I find this is quite repetitive for me and would save me some time.
gralooks promising). If not, you need to come up with something yourself. Having said that, "which shortcut does X?" questions are usually not well-received. Take the tour, read How to Ask.