[MaxBarraclough]

> What happens if you overflow at runtime? A crash, I assume/hope?

In Ada, if range constraints are broken at runtime, a Constraint_Error is raised (or 'thrown', if you prefer). [0] (That's assuming of course that range checks haven't been disabled, which is an option that Ada compilers offer you.)

> I don't see why the default for Java is to have these really nitty-gritty numeric types

At the risk of retreading our earlier discussion:

I think the short answer is performance. Java has lofty goals of abstraction, yes, but it also aims to be pretty fast. If it didn't, its appeal would diminish considerably, so it's reasonable that they struck a balance like this. Same goes for why primitives aren't objects.

[0] https://learn.adacore.com/courses/Ada_For_The_CPP_Java_Devel...

[int_19h]

It depends on the base type - you can get the traditional unsigned integer wraparound behavior, too. But Ada is very explicit about this, to the point of referring to them as "modulo types", and defining them using the mod keyword instead of range:

   type Unsigned_32 is mod 2**32;