Turn some .i files into .swig

[gchatelet]

This helps with the import / export process.

[Mizux]

you are missing all CMakeLists.txt e.g. https://github.com/google/or-tools/blob/main/ortools/algorithms/csharp/CMakeLists.txt#L14-L16

[Mizux]

For the record:

SWIG documentation

SWIG interface file which is usually denoted with a special .i or .swg suffix

ref: https://www.swig.org/Doc4.3/SWIG.html#SWIG_nn3

CMake

builtin UseSWIG.cmake
by default use on .i but you can also use set(SWIG_SOURCE_FILE_EXTENSIONS ".i" ".swig") to override it

cf: https://gitlab.kitware.com/cmake/cmake/-/blob/master/Modules/UseSWIG.cmake?ref_type=heads#L341-L347

Vim

Vim IDE support .swig and .swg and .i (with conflicts ?) as SWIG file type

[0]─[/usr/share/vim/vim91]
[v]─mizux@host %grepc -inH -A 2 "swig" filetype.vim
filetype.vim:2004:" Progress or assembly or Swig
filetype.vim-2005-au BufNewFile,BufRead *.i            call dist#ft#FTi()
filetype.vim-2006-
--
filetype.vim:2537:" Swig
filetype.vim:2538:au BufNewFile,BufRead .swg,.swig setf swig
filetype.vim-2539-

GitHub

rely on linguist to detect file type using:

We use Linguist to perform language detection and to select third-party grammars for syntax highlighting.

ref: https://docs.github.com/en/get-started/writing-on-github/working-with-advanced-formatting/creating-and-highlighting-code-blocks#syntax-highlighting

SWIG:
  type: programming
  extensions:
  - ".i"
  tm_scope: source.c++
  ace_mode: c_cpp
  codemirror_mode: clike
  codemirror_mime_type: text/x-c++src
  language_id: 1066250075

ref: https://github.com/github-linguist/linguist/blob/ddd7a2b4a7f6c8b34345a12a3b87703cbaaebf16/lib/linguist/languages.yml#L6813-L6821

[gchatelet]

New attempt here #4712