Kotlin val three = Money("USD", 100) + Money("USD", 200) 0: new #14 // class Money 3: dup 4: ldc #16 // String USD 6: bipush 100 8: invokespecial #20 // Method Money."":(Ljava/lang/String;I)V 11: new #14 // class Money 14: dup 15: ldc #16 // String USD 17: sipush 200 20: invokespecial #20 // Method Money."":(Ljava/lang/String;I)V 23: invokestatic #26 // Method examplePackage$6fdc46c0.plus:(LMoney;LMoney;)LMoney; Java Money three = Moneys.plus(new Money("USD", 100), new Money("USD", 200)); 0: new #2 // class Money 3: dup 4: ldc #3 // String USD 6: bipush 100 8: invokespecial #4 // Method Money."":(Ljava/lang/String;I)V 11: new #2 // class Money 14: dup 15: ldc #3 // String USD 17: sipush 200 20: invokespecial #4 // Method Money."":(Ljava/lang/String;I)V 23: invokestatic #5 // Method Moneys.plus:(LMoney;LMoney;)LMoney; Data class implementation does not differ much from AutoValue or a hand-rolled value type. The only notable differences is the addition of the copy helper and the number-based accessor methods for value unpacking. Kotlin data class Money(val currency: String, val amount: Int) public final class Money implements kotlin.jvm.internal.KObject { public static final kotlin.reflect.jvm.internal.KClassImpl $kotlinClass; static {}; Code: 0: ldc #2 // class Money 2: invokestatic #91 // Method kotlin/reflect/jvm/internal/InternalPackage.kClassFromKotlin:(Ljava/lang/Class;)Lkotlin/reflect/jvm/internal/KClassImpl; 5: putstatic #93 // Field $kotlinClass:Lkotlin/reflect/jvm/internal/KClassImpl; 8: return public final java.lang.String getCurrency(); Code: 0: aload_0 1: getfield #19 // Field currency:Ljava/lang/String; 4: areturn public final int getAmount(); Code: 0: aload_0 1: getfield #27 // Field amount:I 4: ireturn public Money(java.lang.String, int); Code: 0: aload_1 1: ldc #32 // String currency 3: invokestatic #38 // Method kotlin/jvm/internal/Intrinsics.checkParameterIsNotNull:(Ljava/lang/Object;Ljava/lang/String;)V 6: aload_0 7: invokespecial #40 // Method java/lang/Object."":()V 10: aload_0 11: aload_1 12: putfield #19 // Field currency:Ljava/lang/String; 15: aload_0 16: iload_2 17: putfield #27 // Field amount:I 20: return public final java.lang.String component1(); Code: 0: aload_0 1: getfield #19 // Field currency:Ljava/lang/String; 4: areturn public final int component2(); Code: 0: aload_0 1: getfield #27 // Field amount:I 4: ireturn public final Money copy(java.lang.String, int); Code: 0: aload_1 1: ldc #32 // String currency 3: invokestatic #38 // Method kotlin/jvm/internal/Intrinsics.checkParameterIsNotNull:(Ljava/lang/Object;Ljava/lang/String;)V 6: new #2 // class Money 9: dup 10: aload_1 11: iload_2 12: invokespecial #46 // Method "":(Ljava/lang/String;I)V 15: areturn public static Money copy$default(Money, java.lang.String, int, int); Code: 0: aload_0 1: iload_3 2: iconst_1 3: iand 4: ifeq 12 7: aload_0 8: getfield #19 // Field currency:Ljava/lang/String; 11: astore_1 12: aload_1 13: iload_3 14: iconst_2 15: iand 16: ifeq 24 19: aload_0 20: getfield #27 // Field amount:I 23: istore_2 24: iload_2 25: invokevirtual #50 // Method copy:(Ljava/lang/String;I)LMoney; 28: areturn public java.lang.String toString(); Code: 0: new #55 // class java/lang/StringBuilder 3: dup 4: invokespecial #56 // Method java/lang/StringBuilder."":()V 7: ldc #58 // String Money(currency= 9: invokevirtual #62 // Method java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder; 12: aload_0 13: getfield #19 // Field currency:Ljava/lang/String; 16: invokevirtual #62 // Method java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder; 19: ldc #64 // String , amount= 21: invokevirtual #62 // Method java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder; 24: aload_0 25: getfield #27 // Field amount:I 28: invokevirtual #67 // Method java/lang/StringBuilder.append:(I)Ljava/lang/StringBuilder; 31: ldc #69 // String ) 33: invokevirtual #62 // Method java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder; 36: invokevirtual #71 // Method java/lang/StringBuilder.toString:()Ljava/lang/String; 39: areturn public int hashCode(); Code: 0: aload_0 1: getfield #19 // Field currency:Ljava/lang/String; 4: dup 5: ifnull 14 8: invokevirtual #74 // Method java/lang/Object.hashCode:()I 11: goto 16 14: pop 15: iconst_0 16: bipush 31 18: imul 19: aload_0 20: getfield #27 // Field amount:I 23: iadd 24: ireturn public boolean equals(java.lang.Object); Code: 0: aload_0 1: aload_1 2: if_acmpeq 50 5: aload_1 6: instanceof #2 // class Money 9: ifeq 52 12: aload_1 13: checkcast #2 // class Money 16: astore_2 17: aload_0 18: getfield #19 // Field currency:Ljava/lang/String; 21: aload_2 22: getfield #19 // Field currency:Ljava/lang/String; 25: invokestatic #80 // Method kotlin/jvm/internal/Intrinsics.areEqual:(Ljava/lang/Object;Ljava/lang/Object;)Z 28: ifeq 52 31: aload_0 32: getfield #27 // Field amount:I 35: aload_2 36: getfield #27 // Field amount:I 39: if_icmpeq 46 42: iconst_0 43: goto 47 46: iconst_1 47: ifeq 52 50: iconst_1 51: ireturn 52: iconst_0 53: ireturn } Java @AutoValue public abstract class Money { public abstract String currency(); public abstract int amount(); public static Money of(String currency, int amount) { return new AutoValue_Money(currency, amount); } } final class AutoValue_Money extends Money { AutoValue_Money(java.lang.String, int); Code: 0: aload_0 1: invokespecial #1 // Method Money."":()V 4: aload_1 5: ifnonnull 18 8: new #2 // class java/lang/NullPointerException 11: dup 12: ldc #3 // String Null currency 14: invokespecial #4 // Method java/lang/NullPointerException."":(Ljava/lang/String;)V 17: athrow 18: aload_0 19: aload_1 20: putfield #5 // Field currency:Ljava/lang/String; 23: aload_0 24: iload_2 25: putfield #6 // Field amount:I 28: return public java.lang.String currency(); Code: 0: aload_0 1: getfield #5 // Field currency:Ljava/lang/String; 4: areturn public int amount(); Code: 0: aload_0 1: getfield #6 // Field amount:I 4: ireturn public java.lang.String toString(); Code: 0: new #7 // class java/lang/StringBuilder 3: dup 4: invokespecial #8 // Method java/lang/StringBuilder."":()V 7: ldc #9 // String Money{currency= 9: invokevirtual #10 // Method java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder; 12: aload_0 13: getfield #5 // Field currency:Ljava/lang/String; 16: invokevirtual #10 // Method java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder; 19: ldc #11 // String , 21: invokevirtual #10 // Method java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder; 24: ldc #12 // String amount= 26: invokevirtual #10 // Method java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder; 29: aload_0 30: getfield #6 // Field amount:I 33: invokevirtual #13 // Method java/lang/StringBuilder.append:(I)Ljava/lang/StringBuilder; 36: ldc #14 // String } 38: invokevirtual #10 // Method java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder; 41: invokevirtual #15 // Method java/lang/StringBuilder.toString:()Ljava/lang/String; 44: areturn public boolean equals(java.lang.Object); Code: 0: aload_1 1: aload_0 2: if_acmpne 7 5: iconst_1 6: ireturn 7: aload_1 8: instanceof #16 // class Money 11: ifeq 50 14: aload_1 15: checkcast #16 // class Money 18: astore_2 19: aload_0 20: getfield #5 // Field currency:Ljava/lang/String; 23: aload_2 24: invokevirtual #17 // Method Money.currency:()Ljava/lang/String; 27: invokevirtual #18 // Method java/lang/String.equals:(Ljava/lang/Object;)Z 30: ifeq 48 33: aload_0 34: getfield #6 // Field amount:I 37: aload_2 38: invokevirtual #19 // Method Money.amount:()I 41: if_icmpne 48 44: iconst_1 45: goto 49 48: iconst_0 49: ireturn 50: iconst_0 51: ireturn public int hashCode(); Code: 0: iconst_1 1: istore_1 2: iload_1 3: ldc #20 // int 1000003 5: imul 6: istore_1 7: iload_1 8: aload_0 9: getfield #5 // Field currency:Ljava/lang/String; 12: invokevirtual #21 // Method java/lang/String.hashCode:()I 15: ixor 16: istore_1 17: iload_1 18: ldc #20 // int 1000003 20: imul 21: istore_1 22: iload_1 23: aload_0 24: getfield #6 // Field amount:I 27: ixor 28: istore_1 29: iload_1 30: ireturn }