Don't get me wrong- I agree with the sentiment that crashes are better than corruption. But, as someone else already mentioned, the thread sanitizer does cause

Don't get me wrong- I agree with the sentiment that crashes are better than corruption. But, as someone else already mentioned, the thread sanitizer does cause significant overhead from all of the debug info it holds (maybe a release version could just be performance tuned). But, also, Swift already has asserts that go away in release builds, as you mentioned. So it's at least consistent.