More than one main

[Walter Bright]

On 3/24/2011 4:07 AM, bearophile wrote:
> I receive an error like:
>
> OPTLINK (R) for Win32  Release 8.00.12 Copyright (C) Digital Mars 1989-2010
> All rights reserved. http://www.digitalmars.com/ctg/optlink.html ...   Offset
> 00137H Record Type 00C3 Error 1: Previous Definition Different : __Dmain ---
> errorlevel 1

No mystery there. You have two main()'s. There can be only one.


> Currently in D there is no notion of "main module",

Yes, there is. It's the one that defines main().


> I like to keep a main() in most modules, even the ones that are usually not
> supposed to be the main modules of a program, because I put in their main()
> some demo code that shows what this module does (and a main is useful to run
> unittests too, rdmd has the --main switch for this). Most of my Python
> modules have such demo main code, that runs only if you run them as main
> modules.

That's what the version statement is for:

version (My_Demo)
{
     void main()
     {
         ...
     }
}

There's no reason to add more features to duplicate that.