Why version() ?

[Tim M]

It gets even better with constants and works in static asserts too:


module Vers;

template vers(char[] V)
{
       mixin("version(" ~ V ~ ")
       {
             const bool vers = true;
       }
       else
       {
             const bool vers = false;
       }");
}

const DigitalMars = "DigitalMars";
const X86 = "X86";
const X86_64 = "X86_64";
const Windows = "Windows";
const Win32 = "Win32";
const Win64 = "Win64";
const LittleEndian = "LittleEndian";
const BigEndian = "BigEndian";
const D_Coverage = "D_Coverage";
const D_Ddoc = "D_Ddoc";
const D_InlineAsm_X86 = "D_InlineAsm_X86";
const D_InlineAsm_X86_64 = "D_InlineAsm_X86_64";
const D_LP64 = "D_LP64";
const D_PIC = "D_PIC";
const none = "none";
const all = "all";

int main()
{
       const bool forceLong = false;
       static if(vers!(X86_64) || forceLong)
       {
             long a;
             pragma(msg, "64 bit");
       }
       else
       {
             int a;
             pragma(msg, "32 bit");
       }

       static assert(vers!(LittleEndian) || vers!(BigEndian), "You are a  
weird endian");



       a = 2;

       return a;
}