Added simple example for imcompatible allocators

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-## Custom Include Rules
+# Example-specific
+examples/incompatible_allocators/rust/target/
 
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examples/incompatible_allocators/README.md

@@ -0,0 +1,21 @@
+# incompatible_allocators
+
+## Summary
+
+This example demonstrates undefined behavior caused by mismatched memory allocators between Rust and C++.
+
+## Scenario
+
+- Rust allocates memory using `Box`
+- Ownership is transferred to C++
+- C++ deallocates using `operator delete`
+
+## Problem
+
+Different allocators may use different metadata layouts.  
+Deallocating with the wrong allocator leads to undefined behavior.
+
+## Run
+
+```bash
+./run.sh

examples/incompatible_allocators/cpp/main.cpp

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+#include <cstddef>
+#include <cstdint>
+#include <iostream>
+
+// Function provided by Rust
+extern "C" void pass_to_cpp();
+
+// This function is called by Rust and receives ownership of memory.
+//
+// BUG DEMONSTRATION:
+// The memory was allocated in Rust using its allocator,
+// but we incorrectly deallocate it using C++'s operator delete.
+//
+// This mismatch leads to undefined behavior.
+extern "C" void take_ownership_in_cplusplus(uint32_t* pointer, size_t length) {
+    std::cout << "C++ received array of length: " << length << std::endl;
+
+    // (Optional) Access data safely (just to show it's valid initially)
+    std::cout << "First element: " << pointer[0] << std::endl;
+
+    //  WRONG: Deallocating with C++ allocator
+    //
+    // Why this is UB:
+    // - Rust allocator != C++ allocator
+    // - Metadata layout may differ
+    // - Size assumptions may differ
+    //
+    // This can cause:
+    // - Heap corruption
+    // - Crashes
+    // - Silent memory bugs
+    ::operator delete(pointer, length * sizeof(*pointer));
+}
+
+int main() {
+    std::cout << "Calling Rust code..." << std::endl;
+
+    // This will trigger the whole flow:
+    // Rust allocates → passes pointer → C++ frees incorrectly
+    pass_to_cpp();
+
+    std::cout << "Finished execution." << std::endl;
+    return 0;
+}

examples/incompatible_allocators/run.sh

@@ -0,0 +1,18 @@
+#!/bin/bash
+set -e
+
+echo "=== Building Rust library ==="
+
+cd rust
+cargo build
+cd ..
+
+echo "=== Compiling C++ and linking ==="
+
+# Explicit path to static library (more reliable for CI)
+g++ cpp/main.cpp \
+    rust/target/debug/libincompatible_allocators.a \
+    -o example
+
+echo "=== Running example ==="
+./example

examples/incompatible_allocators/rust/Cargo.toml

@@ -0,0 +1,7 @@
+[package]
+name = "incompatible_allocators"
+version = "0.1.0"
+edition = "2021"
+
+[lib]
+crate-type = ["staticlib"]

examples/incompatible_allocators/rust/src/lib.rs

@@ -0,0 +1,30 @@
+// This function is exposed to C++ via FFI.
+//
+// It allocates memory in Rust using Box (Rust's global allocator),
+// then transfers ownership of that memory to C++.
+//
+// IMPORTANT:
+// The memory MUST be deallocated using the SAME allocator (Rust's),
+// otherwise this leads to undefined behavior.
+#[no_mangle]
+pub extern "C" fn pass_to_cpp() {
+    // Allocate a fixed-size array on the heap using Rust's allocator
+    let list = Box::new([1u32, 2, 3, 4, 5, 6, 7]);
+
+    // Convert Box into a raw pointer.
+    // This transfers ownership — Rust will NOT automatically free this memory anymore.
+    let ptr = Box::into_raw(list);
+
+    // SAFETY:
+    // - We are passing a valid pointer and correct length
+    // - We are assuming C++ will handle ownership correctly (this is the bug!)
+    unsafe {
+        take_ownership_in_cplusplus(ptr as *mut u32, 7);
+    }
+}
+
+// Declaration of the C++ function.
+// This tells Rust that the implementation exists on the C++ side.
+extern "C" {
+    fn take_ownership_in_cplusplus(pointer: *mut u32, length: usize);
+}