Same for C#. Any narrowing truncation needs to be an explicit cast. Widening is typically allowed implicitly, although in the case of the 'decimal' (128 bit struct representing a 'higher precision' floating point) type you still need an explicit cast from a 'double', since there are cases where that conversion can still change the value or fail (i.e. Infinity/NaN)

It can catch people by surprise that Java's narrowing conversions may not preserve the sign. For example, the following is broken:

class TimestampedObject implements Comparable<TimestampedObject> { long timestamp; int compareTo(TimestampedObject other) { return (int)(timestamp - other.timestamp); } ... }

ErrorProne catches this: https://errorprone.info/bugpattern/BadComparable

Noo! This idea is super new and was invented by Go/Rust.