A great read for folks wondering why Java uses type erasure instead of "reified" generics. For the unaware, that means that a List<Integer> is a List<Object> at runtime. I had always wondered about it and why they didn't take the alternative route. For context, C# does have reified types so the actual type parameter is available at runtime.

I personally love reading in depth discussions about counter intuitive engineering decisions like this.

Assertions being built into Java is nice and they've been around since version 1.4. They predate type parameters! I have never seen them being used and the reason always seems to be that because you can't count on them being turned on because they're off by default.

The only theoretical use I can think of it for "executable comments", as in something like the example below, but they're annoying as the IDE will usually complain that it is always true (with no way to specifically disable warning for always true assertions, only always true conditions in general).

if (condition) {
  // Very long block of code
} else {
  assert !condition; // Primarily a reminder for when the if condition is not easily seen
}

Here it doesn't matter if the assertion is executed or not because it is just a reminder. The idea being that code sticks out more than a comment.