[adgjlsfhk1]

Right but the reason they don't follow those 2 rules is that using them would require not using most C++ libraries that don't follow the rules, and would introduce performance regressions that negate the main reason they chose C++ in the first place.

[Dylan16807]

This entire post is about a gradual transition. You don't have to avoid libraries that break the rules, you just have to accept that they're outside the safe zone.

For performance, you'll have to be more specific about your shared pointer claims. But I bet that it's a very small fraction of C++ functions that need the absolute best performance and can't avoid those performance problems while following the two rules.