How to avoid namespace content indentation in vim?

Question

How to set vim to not indent namespace content in C++?

namespace < identifier >
{
    < statement_list > // Unwanted indentation
}

Surprisingly, 'cinoptions' doesn't provide a way to edit namespace content indentation.

Answer 1

I use cpp.vim which is inspired by the Google C++ Style Guide. Among other things, that script does what you're asking.

Answer 2

cpp.vim will solve your problem, but if you don't want the full-blown Google coding style then just take a peek at the plugin source and see how it handles namespaces. It's super simple:

function! IndentNamespace()
  let l:cline_num = line('.')
  let l:pline_num = prevnonblank(l:cline_num - 1)
  let l:pline = getline(l:pline_num)
  let l:retv = cindent('.')
  while l:pline =~# '\(^\s*{\s*\|^\s*//\|^\s*/\*\|\*/\s*$\)'
    let l:pline_num = prevnonblank(l:pline_num - 1)
    let l:pline = getline(l:pline_num)
  endwhile
  if l:pline =~# '^\s*namespace.*'
    let l:retv = 0
  endif
  return l:retv
endfunction

setlocal indentexpr=IndentNamespace()

In essence all you do is match the last non-blank line against /^\s*namespace/, and if it matches return 0 (as the indent position for indentexpr); otherwise return Vim's builtin cindent mechanism's value.

I essentially stole the code from the plugin, stripped anything that isn't namespace-related and renamed the indent function to IndentNamespace(). Save this as ~/.vim/indent/cpp.vim.

Answer 3

I've configured vim to not indent for the namespace. These are the relevant lines in my vimrc:

autocmd Filetype cpp set shiftwidth=2
set cino=>2(0^-2g0h2

Frankly, I don't remember how to interpet the cino statement, but :help cinoptions should help in deciphering it. One caveat: I think it's configured to not indent when using a format like so:

namespace foo 
{ // <- curly bracket on next line
...

versus

namespace foo { // <- same line

Since I put the curly bracket on the next line exclusively for namespaces, it does what I want, but it might not work if you use that style for other function declarations, for, etc.