Recommended coding convention for combining unix and windows code ?

[FreeSlave via Digitalmars-d-learn]

On Tuesday, 7 June 2016 at 15:33:57 UTC, chmike wrote:
> Hello
>
> I'm writing some code that I want to be portable across Posix 
> and Windows.
>
> What is the recommended code convention for such type of code ?
>
> 80% of the class implementation is the same for both OS.
>
> Should I write the following and copy past the 80%
>
> version( Windows ) {
>     import core.sys.windows;
>     class MyInfo {...}
> } else version( Posix ) {
>     import core.sys.posix;
>     class MyInfo {...}
> } else {
>     static assert(false, "Unsupported platform");
> }
>
> or should I do it the C way with multiple embedded static if... 
> ?
>
> version( Windows ) {
>     import core.sys.windows;
> } else {  //Posix
>     import core.sys.posix;
> }
>
> class MyInfo {
>     ...
>     static if(windows) {
>     enum Value {...}
>     } static else {  //Posix
>     enum Value {...}
>     }
>     ...
> }

I think there's no need for copy-paste approach in user code when 
the most parts are shared.

Copy-pasting would eventually make classes out of sync in terms 
of function declarations (parameters, attributes) which in its 
turn will lead to unexpected bugs and errors when compiling on 
other platform.
Also copy-pasting of class would require to copy-paste 
documentation comments and unittests, which is another PITA. You 
can write declarations specifically for documentation comments, 
but it means even more copy-pasting and can lead to the situation 
where documentation is out of sync with actual declarations.

By the way phobos has example of copy-paste - DirEntry struct. 
And its functions have different attributes across Windows and 
Posix (e.g. const vs non-const) which really hurts cross-platform 
programming.