Add mapping to rename include guards in c/cpp

autoload/do.vim

@@ -54,3 +54,17 @@ function! do#cursor_highlight_groups()
   let l:lo = synIDattr(synIDtrans(synID(line('.'),col('.'),1)),'name')
   echo 'hi<'.l:hi.'> trans<'.l:trans.'> lo<'.l:lo.'>'
 endfunction
+
+" Rename C/C++ include guard
+function! do#rename_include_guard(old)
+  " Prompt for new guard name
+  let l:new = input('Rename include guard: ', a:old)
+  " Set a mark to jump back to
+  normal mr
+  " Replace the old guard name with the new one
+  exec '%s/\(#ifndef\|#define\|#endif\s\+\/\/\)\s\+\zs'.a:old.'/'.l:new.'/g'
+  " Stop highlighting search results
+  nohlsearch
+  " Jump back to the set mark
+  normal 'r
+endfunction