Maybe D was wrong on contracts

[Richard (Rikki) Andrew Cattermole]

Two known problems with contracts:

1.   =inclusiveincontracts 'in' contracts of overridden methods must be 
a superset of parent contract 
(https://dlang.org/changelog/2.095.0.html#inclusive-incontracts)

2. the decision to emit must be done by the caller, not the callee's 
compilation flags. Nobody has wanted to fix this yet (although approved).

To quote Mike:

"We approved enabling the following switches in a future edition: 
fieldwise, nosharedaccess, inclusiveincontracts, fiximmutableconv, and 
systemvariables."