3 ms·

Can a turing-complete type system be sanely considered safe?

• dbaupp 8y ago
  Turing completeness of the type system isn't what causes C++'s unsafety: in a sense, being turing complete theoretically allows encoding more safety into the type system. It also allows encoding more impossible-to-write-a-program into the type system, but that's orthogonal (plus, if you can't compile anything, you can't run anything unsafe!). C++ improves on C in some respects, but still suffers from undefined behaviours like use-after-free/dangling references, dereferencing of null (e.g. a moved-from unique_ptr) and iterator invalidation, none of which are caused by a Turing complete type system (they all, in various forms, exist in C too).