This doesn't track at all for me. Rust provides strong guarantees around accessing discriminated unions. The net effect of which is that the code you write has

This doesn't track at all for me. Rust provides strong guarantees around accessing discriminated unions. The net effect of which is that the code you write has the "railway style" error handling that you get with exceptions in the trivial case (propagate the error). It even has a convenient syntactic shorthand for this `?`. In non-trivial cases they are equivalent too. For example, collections need to maintain at a minimum a valid state in the presence of types with exception-throwing (fallible) constructors. This is a mess with or without exceptions in basically the same way. It's such a mess that the C++ standard allows for unspecified behavior of `std::vector::push_back` if the contained type has a throwing move constructor. Throwing move constructors are of course ridiculous but nonetheless allowed. And that I would say is the biggest flaw with exceptions: they presume the fallibility of everything by default. This is not only brain damaging, it actively creates situations where there are no good options.