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AndrewAtAvenzaa4z
AndrewAtAvenza
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a4z
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Add support for equality operators via new 'requires' keyword for interfaces (#169)
* Added support for 'requiring' (will change to 'requires' eventually) * Renamed 'requiring' to 'requires' * Implemented basic equality for C++ & Java * Added support for hashCode() * Accidentally changed 'Bool' to 'I32' -- reverting * Different approaching using methods equals() & hashCode() as static members of a class-in-a-class Operators. * Switched from const std::shared_ptr<>& to const& for parameters to equals() & hashCode() * Moved prototype for native_hash_code() inside requires-if-statement block; should fix unit test failure. * New way of getting sbt (#172) December 2024 CI runners don't have sbt anymore Therefore, install it via actions, fix #171 * Added support for 'requiring' (will change to 'requires' eventually) * Renamed 'requiring' to 'requires' * Implemented basic equality for C++ & Java * Added support for hashCode() * Accidentally changed 'Bool' to 'I32' -- reverting * Different approaching using methods equals() & hashCode() as static members of a class-in-a-class Operators. * Switched from const std::shared_ptr<>& to const& for parameters to equals() & hashCode() * Moved prototype for native_hash_code() inside requires-if-statement block; should fix unit test failure. * Reorganized logic to support call from C++ to Java (needs JNI hookups) * Removed debugging lines (caused unit tests to fail) * Updated with scalafmtAll * Added integration test * Applied formatting * Operator methods now conform to the ID settings * Removed old test code for reversing the 'requires' directive from C++ to Java * Fixed formatting * * added support for `ord` as implementing Java's Comparable<T>::compareTo() calling through to Operators::compare() * updated unit test to include tests for eq, ord & eq+ord * Add documentation for requires --------- Co-authored-by: Harald <harald.achitz@gmail.com>
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‎docs/idl.md‎

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@@ -298,6 +298,45 @@ have special effects in C++:
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- `static` methods will become a static method of the C++ class, which can be called from other languages without an object.
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This is often useful for factory methods to act as a cross-language constructor.
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#### Requires methods
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```
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another_interface = interface +c +j {
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method_returning_nothing(value: i32);
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} requires (eq, ord)
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```
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For interface types, Haskell-style "requires" declarations are supported to generate otherwise unavailable operator-like
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methods like equalTo(), hashCode(), and compare(). Similar to how Djinni is capable of generating equality and order
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comparators for records, "requires" declarations create overloaded operators in Java that call through to methods in C++
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that can be implemented using the desired logic.
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In the example above, equality & ordering functions would be generated like so:
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```
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class AnotherInterface {
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public:
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virtual ~AnotherInterface() {}
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virtual void MethodReturningNothing(int32_t value) = 0;
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class Operators {
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public:
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// these are generated by specifying 'requires(eq)'
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static bool Equals(const AnotherInterface& left, const AnotherInterface& right);
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static int32_6 Hash(const AnotherInterface& object);
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// this is generated by specifying 'requires(ord)'
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static int32_t Compare(const AnotherInterface& left, const AnotherInterface& right);
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};
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};
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```
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!!! note
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- Adding "requires(ord)" will make the generated Java class derive from "Comparable<>".
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- Currently, only Java supports "requires"; other languages will simply ignore the notation.
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#### Exception Handling
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When an interface implemented in C++ throws a `std::exception`, it will be translated to a
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`java.lang.RuntimeException` in Java, an `NSException` in Objective-C, a `RuntimeError` in Python,

‎src/it/resources/expected/requires/cpp-headers/requires_all_interface.hpp‎

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// AUTOGENERATED FILE - DO NOT MODIFY!
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// This file was generated by Djinni from requires.djinni
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#pragma once
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class RequiresAllInterface {
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public:
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virtual ~RequiresAllInterface() {}
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virtual bool some_method() = 0;
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class Operators {
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public:
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static bool equals(const RequiresAllInterface& left, const RequiresAllInterface& right);
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static int32_t hash_code(const RequiresAllInterface& object);
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static int32_t compare(const RequiresAllInterface& left, const RequiresAllInterface& right);
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};
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};

‎src/it/resources/expected/requires/cpp-headers/requires_eq_interface.hpp‎

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// AUTOGENERATED FILE - DO NOT MODIFY!
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// This file was generated by Djinni from requires.djinni
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#pragma once
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class RequiresEqInterface {
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public:
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virtual ~RequiresEqInterface() {}
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virtual bool some_method() = 0;
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class Operators {
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public:
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static bool equals(const RequiresEqInterface& left, const RequiresEqInterface& right);
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static int32_t hash_code(const RequiresEqInterface& object);
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};
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};

‎src/it/resources/expected/requires/cpp-headers/requires_ord_interface.hpp‎

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// AUTOGENERATED FILE - DO NOT MODIFY!
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// This file was generated by Djinni from requires.djinni
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#pragma once
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class RequiresOrdInterface {
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public:
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virtual ~RequiresOrdInterface() {}
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virtual bool some_method() = 0;
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class Operators {
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public:
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static int32_t compare(const RequiresOrdInterface& left, const RequiresOrdInterface& right);
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};
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};

‎src/it/resources/expected/requires/generated-files.txt‎

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src/it/resources/result/requires/cpp-headers/requires_eq_interface.hpp
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src/it/resources/result/requires/cpp-headers/requires_ord_interface.hpp
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src/it/resources/result/requires/cpp-headers/requires_all_interface.hpp
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src/it/resources/result/requires/java/RequiresEqInterface.java
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src/it/resources/result/requires/java/RequiresOrdInterface.java
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src/it/resources/result/requires/java/RequiresAllInterface.java
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src/it/resources/result/requires/jni/djinni_jni_main.cpp
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src/it/resources/result/requires/jni-headers/requires_eq_interface.hpp
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src/it/resources/result/requires/jni/requires_eq_interface.cpp
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src/it/resources/result/requires/jni-headers/requires_ord_interface.hpp
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src/it/resources/result/requires/jni/requires_ord_interface.cpp
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src/it/resources/result/requires/jni-headers/requires_all_interface.hpp
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src/it/resources/result/requires/jni/requires_all_interface.cpp

‎src/it/resources/expected/requires/java/RequiresAllInterface.java‎

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// AUTOGENERATED FILE - DO NOT MODIFY!
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// This file was generated by Djinni from requires.djinni
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package djinni.it;
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import java.util.concurrent.atomic.AtomicBoolean;
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public abstract class RequiresAllInterface implements Comparable<RequiresAllInterface> {
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public abstract boolean someMethod();
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private static final class CppProxy extends RequiresAllInterface
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{
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private final long nativeRef;
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private final AtomicBoolean destroyed = new AtomicBoolean(false);
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private CppProxy(long nativeRef)
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{
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if (nativeRef == 0) throw new RuntimeException("nativeRef is zero");
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this.nativeRef = nativeRef;
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}
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private native void nativeDestroy(long nativeRef);
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public void _djinni_private_destroy()
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{
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boolean destroyed = this.destroyed.getAndSet(true);
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if (!destroyed) nativeDestroy(this.nativeRef);
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}
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@SuppressWarnings("deprecation")
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protected void finalize() throws java.lang.Throwable
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{
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_djinni_private_destroy();
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super.finalize();
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}
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@Override
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public boolean someMethod()
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{
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assert !this.destroyed.get() : "trying to use a destroyed object";
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return native_someMethod(this.nativeRef);
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}
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private native boolean native_someMethod(long _nativeRef);
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@Override
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public boolean equals(Object obj) {
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assert !this.destroyed.get() : "trying to use a destroyed object";
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if (!(obj instanceof RequiresAllInterface)) {
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return false;
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}
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return native_operator_equals(this.nativeRef, (RequiresAllInterface)obj);
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}
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private native boolean native_operator_equals(long _nativeRef, RequiresAllInterface other);
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@Override
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public int hashCode() {
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assert !this.destroyed.get() : "trying to use a destroyed object";
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return native_hash_code(this.nativeRef);
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}
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private native int native_hash_code(long _nativeRef);
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@Override
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public int compareTo(RequiresAllInterface obj) {
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assert !this.destroyed.get() : "trying to use a destroyed object";
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return native_compare(this.nativeRef, obj);
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}
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private native int native_compare(long _nativeRef, RequiresAllInterface other);
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}
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}

‎src/it/resources/expected/requires/java/RequiresEqInterface.java‎

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// AUTOGENERATED FILE - DO NOT MODIFY!
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// This file was generated by Djinni from requires.djinni
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package djinni.it;
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import java.util.concurrent.atomic.AtomicBoolean;
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public abstract class RequiresEqInterface {
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public abstract boolean someMethod();
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private static final class CppProxy extends RequiresEqInterface
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{
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private final long nativeRef;
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private final AtomicBoolean destroyed = new AtomicBoolean(false);
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private CppProxy(long nativeRef)
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{
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if (nativeRef == 0) throw new RuntimeException("nativeRef is zero");
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this.nativeRef = nativeRef;
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}
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private native void nativeDestroy(long nativeRef);
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public void _djinni_private_destroy()
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{
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boolean destroyed = this.destroyed.getAndSet(true);
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if (!destroyed) nativeDestroy(this.nativeRef);
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}
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@SuppressWarnings("deprecation")
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protected void finalize() throws java.lang.Throwable
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{
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_djinni_private_destroy();
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super.finalize();
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}
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@Override
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public boolean someMethod()
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{
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assert !this.destroyed.get() : "trying to use a destroyed object";
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return native_someMethod(this.nativeRef);
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}
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private native boolean native_someMethod(long _nativeRef);
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@Override
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public boolean equals(Object obj) {
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assert !this.destroyed.get() : "trying to use a destroyed object";
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if (!(obj instanceof RequiresEqInterface)) {
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return false;
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}
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return native_operator_equals(this.nativeRef, (RequiresEqInterface)obj);
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}
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private native boolean native_operator_equals(long _nativeRef, RequiresEqInterface other);
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@Override
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public int hashCode() {
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assert !this.destroyed.get() : "trying to use a destroyed object";
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return native_hash_code(this.nativeRef);
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}
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private native int native_hash_code(long _nativeRef);
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}
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}

‎src/it/resources/expected/requires/java/RequiresOrdInterface.java‎

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// AUTOGENERATED FILE - DO NOT MODIFY!
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// This file was generated by Djinni from requires.djinni
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package djinni.it;
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import java.util.concurrent.atomic.AtomicBoolean;
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public abstract class RequiresOrdInterface implements Comparable<RequiresOrdInterface> {
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public abstract boolean someMethod();
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private static final class CppProxy extends RequiresOrdInterface
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{
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private final long nativeRef;
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private final AtomicBoolean destroyed = new AtomicBoolean(false);
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private CppProxy(long nativeRef)
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{
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if (nativeRef == 0) throw new RuntimeException("nativeRef is zero");
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this.nativeRef = nativeRef;
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}
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private native void nativeDestroy(long nativeRef);
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public void _djinni_private_destroy()
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{
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boolean destroyed = this.destroyed.getAndSet(true);
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if (!destroyed) nativeDestroy(this.nativeRef);
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}
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@SuppressWarnings("deprecation")
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protected void finalize() throws java.lang.Throwable
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{
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_djinni_private_destroy();
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super.finalize();
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}
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@Override
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public boolean someMethod()
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{
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assert !this.destroyed.get() : "trying to use a destroyed object";
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return native_someMethod(this.nativeRef);
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}
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private native boolean native_someMethod(long _nativeRef);
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@Override
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public int compareTo(RequiresOrdInterface obj) {
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assert !this.destroyed.get() : "trying to use a destroyed object";
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return native_compare(this.nativeRef, obj);
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}
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private native int native_compare(long _nativeRef, RequiresOrdInterface other);
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}
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}

‎src/it/resources/expected/requires/jni-headers/requires_all_interface.hpp‎

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// AUTOGENERATED FILE - DO NOT MODIFY!
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// This file was generated by Djinni from requires.djinni
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#pragma once
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#include "djinni/jni/djinni_support.hpp"
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#include "requires_all_interface.hpp"
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namespace djinni_generated {
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class RequiresAllInterface final : ::djinni::JniInterface<::RequiresAllInterface, RequiresAllInterface> {
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public:
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using CppType = std::shared_ptr<::RequiresAllInterface>;
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using CppOptType = std::shared_ptr<::RequiresAllInterface>;
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using JniType = jobject;
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using Boxed = RequiresAllInterface;
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~RequiresAllInterface();
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static CppType toCpp(JNIEnv* jniEnv, JniType j) { return ::djinni::JniClass<RequiresAllInterface>::get()._fromJava(jniEnv, j); }
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static ::djinni::LocalRef<JniType> fromCppOpt(JNIEnv* jniEnv, const CppOptType& c) { return {jniEnv, ::djinni::JniClass<RequiresAllInterface>::get()._toJava(jniEnv, c)}; }
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static ::djinni::LocalRef<JniType> fromCpp(JNIEnv* jniEnv, const CppType& c) { return fromCppOpt(jniEnv, c); }
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private:
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RequiresAllInterface();
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friend ::djinni::JniClass<RequiresAllInterface>;
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friend ::djinni::JniInterface<::RequiresAllInterface, RequiresAllInterface>;
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};
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} // namespace djinni_generated

‎src/it/resources/expected/requires/jni-headers/requires_eq_interface.hpp‎

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// AUTOGENERATED FILE - DO NOT MODIFY!
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// This file was generated by Djinni from requires.djinni
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#pragma once
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#include "djinni/jni/djinni_support.hpp"
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#include "requires_eq_interface.hpp"
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namespace djinni_generated {
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class RequiresEqInterface final : ::djinni::JniInterface<::RequiresEqInterface, RequiresEqInterface> {
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public:
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using CppType = std::shared_ptr<::RequiresEqInterface>;
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using CppOptType = std::shared_ptr<::RequiresEqInterface>;
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using JniType = jobject;
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using Boxed = RequiresEqInterface;
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~RequiresEqInterface();
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static CppType toCpp(JNIEnv* jniEnv, JniType j) { return ::djinni::JniClass<RequiresEqInterface>::get()._fromJava(jniEnv, j); }
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static ::djinni::LocalRef<JniType> fromCppOpt(JNIEnv* jniEnv, const CppOptType& c) { return {jniEnv, ::djinni::JniClass<RequiresEqInterface>::get()._toJava(jniEnv, c)}; }
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static ::djinni::LocalRef<JniType> fromCpp(JNIEnv* jniEnv, const CppType& c) { return fromCppOpt(jniEnv, c); }
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private:
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RequiresEqInterface();
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friend ::djinni::JniClass<RequiresEqInterface>;
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friend ::djinni::JniInterface<::RequiresEqInterface, RequiresEqInterface>;
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};
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} // namespace djinni_generated

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