created July 21, 2003 · complexity basic · author Morten Fjord-Larsen · version 5.7
C/C++ header files should be guarded against multiple inclusions using preprocessor directives, e.g.:
#ifndef FOO_H #define FOO_H /* Declarations. */ #endif
Placing the following snippet in your vimrc file, makes Vim insert these preprocessor gates automatically, when a new header file is created:
function! s:insert_gates() let gatename = substitute(toupper(expand("%:t")), "\\.", "_", "g") execute "normal! i#ifndef " . gatename execute "normal! o#define " . gatename . " " execute "normal! Go#endif /* " . gatename . " */" normal! kk endfunction autocmd BufNewFile *.{h,hpp} call <SID>insert_gates()
Comments
TO DO
The following is from a proposed new tip that has now been deleted. What is required to make this work? It assumes you start with something?
Here is an alternative, intended to produce:
#ifndef __FILENAME_H #define __FILENAME_H #endif //__FILENAME_H
This will add this kind of block at the top of a new .h file at the press of a key. Add to your vimrc file:
nnoremap <F12> "%phr_I#ifndef __<Esc>gUwyypldwidefine <Esc>yypldwiendif //<Esc>O<Esc>
This is another alternative, also a mapping, intended to produce more verbosely-commented boilerplate but otherwise similar to the above:
:nnoremap <C-F12> "%phr_g0gUw<Esc>I#ifndef __<Esc>g$yiwo<Esc>pI# define <Esc>gg<Esc>A /* Guard against multiple header inclusion error */<Esc>ggjo<Esc>I#endif /* end if-not-def <Esc>pA */<Esc>2O<Esc>
Produces when run on "Phoohaa.h" (must be in that file's working directory):
#ifndef __PHOOHAA_H /* Guard against multiple header instance error */ # define __PHOOHAA_H #endif /* end if-not-def __PHOOHAA_H */
Please note however that using double underscores anywhere in your include guard names is not recommended, and symbols starting with a double underscore including defines are reserved for use by the compiler. So in the above example it is best to use:
#ifndef FILENAME_H #define FILENAME_H ....
For more information, see: http://stackoverflow.com/questions/228783/what-are-the-rules-about-using-an-underscore-in-a-c-identifier