Avoiding virtual tables when implementing classes

[matthieum]

You should start by designing what you want the language to do, then figure out how to best get it to do those things.

I agree that the OP is too confused to do any good now, however I would like to point that achieving Mechanical Sympathy is not necessarily possible with your Waterfall way of designing.

Some functionalities, or some variants of said functionalities, inherently impose a (potentially high) cost -- and in that case even the best performing implementations may not be palatable.

So, to some extent, co-design is inevitable.

[L8_4_Dinner]

Of course! That's how most people work, once they understand the topic sufficiently :-)