GoKawiilJEP 401 value classes land as preview in JDK 28, with performance caveats
JDK 28 has integrated JEP 401, a Project Valhalla milestone, as a preview feature that introduces value classes to the JVM. The author explains that these classes drop object identity, letting the JVM flatten and scalarize data in memory rather than always using pointer-based references, which can boost performance in many cases.