Prototype buildsystem "Drake"

[Timon Gehr]

Nick Sabalausky wrote:
> Ultimately, I think going with a rake/scons-like build-system approach just
> allows for a little bit more boilerplate to be removed, which is good for
> something like a buildscript. For example, if done as a library, once you've
> defined all your targets, you'd have to call some function to actually do
> the build. As a build system, defining the targets is all you need to do,
> and the build gets invoked automatically. It's kinda like how dmain() calls
> the user's main() instead of the work inside dmain() being a library
> functions that the main() author needs to call. Plus, as a build-system, the
> "void main(string[] args) {" part can eventually be removed (once sticking
> normally-module-level things inside a function is mature enough, if it isn't
> already).

It is not mature at all.
Module-level things inside functions do not currently work well:

Eg:

- No forward references.
- No forward references, reloaded:
void main(){
    int foo();
    int bar(){return foo();} // ok
    int foo(){return 100;}   // nope, *!* this is called a "redefinition" *!*
}


- No (template) overloading:
void main(){
    int foo(int x){return x;}
    double foo(double x){return x;} // nope
    int bar(int x)(){return x;}
    double bar(double x)(){return x;} // nope
}

Those limitations are very itchy (at least for the kind of stuff I'd like to be
doing), and should be removed.

Cheers,
-Timon