[jjnoakes]

Safe pockets in ambient unsafety does have benefits though. For example, some code has a higher likelihood of containing undefined behavior (code that manipulates pointers and offsets directly, parsing code, code that deals with complex lifetimes and interconnected graphs, etc), so converting just that code to safe code would have a high ROI.

And once you get to the point where a large chunk of code is in safe pockets, any bugs that smell of undefined behavior only require you to look at the code outside of the safe pockets, which hopefully decreases over time.

There are also studies that show that newly written code tends to have more undefined behavior due to its age, so writing new code in safe pockets has a lot of benefit there too.