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• Create a POJO using an experimental javac, with an annotation ValueCapableClass (jvm.internal.value.ValueCapableClass)
  • JVM will derive a Derived Value Class (DVC) from this defined "box" which we call the Value Capable Class (VCC)
  • DVC contains an immutable copy of the instance fields from the VCC
• Work with MethodHandles and experimental reflection package ValueType (jdk.experimental.value.ValueType)
• Or spin your own byte codes
  
  • experimental MethodBuilder (jdk/experimental/value.MethodHandleBuilder)
  • future: ASM support is planned

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• Code samples
  • See directory jdk/test/valhalla/mvt in your repository
    • e.g. MethodHandlesTest

Run Experimental MVT

• java -Xverify:none -XX:+EnableMVT <Test>
• Command-line flags: Minimal Value Types Command-line Optionsjava: use -Xverify:none -XX:+EnableMVT

Filing Bugs

• File openjdk bugs with synopsis starting with "[MVT]" and labels: "mvt"

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• Minimal Value Types Command-line Options
• Youtube JVMLS 2017: Minimal Value Types: Origins and Programming Model
  
• Youtube JVMLS 2017: Minimal Value Types: Under the Hood
  

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