I used to use folding to fold functions in C/C++ from the "{" to the "}", but I wanted a way to fold the prototype as well. Using foldexpr allows this.

function FoldBrace()
  if getline(v:lnum+1)[0] == '{'
    return '>1'
  endif
  if getline(v:lnum)[0] == '}'
    return '<1'
  endif
  return foldlevel(v:lnum-1)
endfunction
set foldexpr=FoldBrace()
set foldmethod=expr

Note that this will only work if you put the braces on lines by themselves in the very first column, ie:

 void func()
 {
   ....
 }

Comments

Johannes Zellner started to define a fold(ing?) plugin for C and C++. I've tried to enhanced it a little, but unfortunately, it is still imperfect.

See http://hermitte.free.fr/vim/ressources/vimfiles/fold/c-fold.vim

--Luc Hermitte 13:39, 7 June 2007 (UTC), August 2, 2003 18:34

That certainly is more featureful than my version. But I prefer to use foldnestmax=1 - I find it annoying to have more than 1 fold level.

I've modified my fold function to work if the { is on the same line as the function, ie:

void bla() {
}

I'd like to be able to use v:foldstart in my fold function so I can check that the } has the same indent as the line containing the {. That way I could match braces that aren't in the first column. But this is good enough for my purposes.

function FoldBrace()
  if getline(v:lnum+1)[0] == '{'
    return 1
  endif
  if getline(v:lnum) =~ '{'
    return 1
  endif
  if getline(v:lnum)[0] =~ '}'
    return '<1'
  endif
  return -1
endfunction