D alternative for C/C++ -Dfoo=42

[Tobias Pankrath]

> module myproggy;
> import std.stdio;
> enum foo = 5;
> enum bar = "walter";
>
> int main() {
>   writeln(bar);
>   return foo;
> }
>
> ... and you call compiler like:
>   dmd myproggy.d -Dfoo=42 -Dbar=hello
>
> smart, new D compiler would replace enums (iff they exist in 
> the source code) with the given arguments, so when you run 
> myproggy, you get "walter" as output, and the exit code is 42.

I don't like it. I would prefer a CTFE-able counter part to 
boost::program_options that generates thouse enums from a config 
file.