Conditional compilation inside asm and enum declarations

[Andrei Alexandrescu]

Walter Bright wrote:
> Andrei Alexandrescu wrote:
>> Then I have the function right there with all versioned 
>> implementations. To me that seems better than Phobos' existing style 
>> of version'ing large portions of code, which inevitably results in 
>> duplicating a lot of the functionality in two places.
> 
> I wouldn't consider Phobos to be an exemplary example of how to do 
> versioning, though it should be. I think much of it, like std.file, 
> should be split off into os-dependent "personality" modules, much like 
> the os api modules have been.

That would exacerbate code duplication. Consider:

version(Windows) void[] read(in char[] name)
{
     ...
}

version(Posix) void[] read(in char[] name)
{
     ...
}

S readText(S = string)(in char[] name)
{
    ...
}

In my approach they are laid as you see them, which I find very 
well-organized. In your approach you'd define several files each 
specialized for an OS, which would duplicate readText, or put readText 
into a common file and have it include platform-specific files. Both 
solutions are unnecessarily complicated to the simple and clear code above.


Andrei