[Ygg2]

> Compiler being obtuse and not being able to figure when it is safe to "break rules" is the problem.

Compiler afaik will never be able to correctly 100% identify you are or aren't breaking some properties due to Rice's Theorem.

That said, you're committing a Nirvana fallacy. Perfect doesn't prevent improvement.

E.g. seatbelts don't prevent being stabbed by a large metal pole, ergo it's useless.

Every week I see newbies coming and asking why won't compiler allow this - and then point a hugely unsafe action.

Hell, I ran into a similar issue. I wanted to expose something mutable as immutable. My argumentation was but it was immutable at time of calling. However as someone in Rust discord pointed, using that you could cause UB trivially.

[FpUser]

>"Compiler afaik will never be able to correctly 100% identify"

Nobody here is talking about 100%. I responded to a post that has left me with the impression that it is up to the user to bend backwards and make their brains work as a compiler rather than try to improve compiler.

[Ygg2]

> that it is up to the user to bend backwards and make their brains work as a compiler

What do you mean? You always have to track lifetimes and what outlives what (i.e. work of a compiler). Especially in C++. Not doing that results in UB.

In Rust you have a compiler double checking you. And it errs on side of caution. And no, errors aren't horrible, they come with suggestions for fixing them.