Dual D2/D1 code base

[Jason House]

I don't know what made me think of it, but could a feature very similar to Descent's compile-time view be used for generating D1 code from D2 code? It should allow striping of const, immutable, nothrow, shared, and pure from D2 code with relative ease. It obviously would not solve everything, but I think it could allow Tango to use a single code base... Several Tango-based D1 libraries could then follow and support both D1 and D2. 

Thoughts?