supporting DMD-1.016 and DMD-2.000 with the same source code

[Carlos Santander]

Thomas Kuehne escribió:
> 4) class invariants
> ===================
> 
> This is the only real trouble spot so far. DMD-1 uses
> 	invariant{ ... assert(...); ... }
> however DMD-2 uses
> 	invariant(){ ... assert(...); ... }
> 
> There are basically two approaches. Both require dmd_version from
> 1) "What compiler am I running?" (see above). First the complete
> mixin solution:
> 
> # class Foo : Object{
> #    int x;
> #
> #    mixin("invariant" ~ (dmd_version < 2 ? "" : "()") ~
> #       "{
> #          assert(x < 100);
> #       }");
> # }
> 
> This might be a quick hack however in most cases you are going to
> lose nice features like syntax highlighting. Invariants are
> prohibited from calling 'public' member function but calling
> 'private' member functions is OK:
> 
> # const char[] invariantCall = "invariant" ~ (dmd_version < 2 ? "" : "()")
> #    ~ "{ invariant_(); }";
> #
> # class Foo : Object{
> #    int x;
> #
> #    mixin(invariantCall);
> #
> #    private void invariant_(){
> #       assert(x < 100);
> #    }
> # }
> 

To avoid this ugly hack, how about supporting invariant(){} in Dv1?


-- 
Carlos Santander Bernal