I mean that the P2900 syntax is enough for assertions; inline semantic forcing IMO actually decreases safety (in the same way that to keep an exposed gas pipe safe, you should mark it loudly, and not try to build massive walls, because it statistically leads to fewer accidents).

We will need a massive investment into static analysis for the predicates to be useful for proving programs correct without runtime checks, which is where the real step-change will come from. In my opinion.