how to let mini.comment comment c++ code with //... instead of /*...*/

[lainegates]

Is there a config parameter that let mini.comment comment c++ code with //... instead of /*...*/

[echasnovski]

'mini.comment' infers comment structure based on 'commentstring' option.

My suggestion would be to create a file 'after/ftplugin/cpp.lua' and put vim.bo.commentstring = '// %s' line there.

[lainegates]

@echasnovski Thanks!
Could I make this setting effective only for C++ code? How to do it?

[echasnovski]

Could I make this setting effective only for C++ code? How to do it?

Yes:

My suggestion would be to create a file 'after/ftplugin/cpp.lua' and put vim.bo.commentstring = '// %s' line there.

[lainegates]

I'm not very familiar with the configuration of nvim. I want to confirm, do you mean to create a directory mini.comment/after/ftplugin/cpp.lua? (which means code of "mini.comment" will be modified.)
Or should it be in ~/.config/nvim/lua/after/ftplugin/cpp.lua?"

[echasnovski]

The '~/.config/nvim/after/ftplugin/cpp.lua' (no 'lua' subdirectory). Files inside 'ftplugin' directory (either directly or inside 'after' directory) are considered to have "filetype plugins" - files which are sourced when 'filetype' option is set to the value same as file's name.
You can read more about plugin structure typing :h 'runtime' (followed by <CR>, a.k.a. <Enter>).

[lainegates]

@echasnovski Thanks! It works, I will read more about plugins.