Reference count (Rc aka shared_ptr) implementation

refcount/Makefile

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+# Only define if needed:
+# TARGET = main.elf
+# SRCS = main.cc
+
+include ../config.mk

refcount/main.cc

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+#include <iostream>
+
+/* RefCounter. Analogous to std::shared_ptr. */
+template <typename T>
+class Rc {
+    T *data;
+    std::size_t *refs;
+
+  public:
+    explicit Rc(const T &); // Copy ctor
+    explicit Rc(T &&);      // Move ctor
+
+    Rc(const Rc &); // Copy ctor
+    Rc(Rc &&);      // Move ctor
+
+    void operator=(const Rc &); // Copy assign
+    void operator=(Rc &&);      // Move assign
+
+    ~Rc();
+    const T &borrow() noexcept;
+    T &borrow_mut() noexcept;
+};
+
+template <typename T>
+Rc<T>::Rc(const T &data)
+    : Rc(std::move(data)) {}
+
+template <typename T>
+Rc<T>::Rc(T &&data)
+    : data(new T(std::move(data)))
+    , refs(new std::size_t(1)) {}
+
+template <typename T>
+Rc<T>::Rc(const Rc &other)
+    : data(other.data)
+    , refs(other.refs) {
+    refs++;
+}
+
+template <typename T>
+Rc<T>::Rc(Rc &&other)
+    : data(other.data)
+    , refs(other.refs) {
+    other.refs = nullptr;
+    other.data = nullptr;
+}
+
+template <typename T>
+void Rc<T>::operator=(const Rc &other) {}
+
+template <typename T>
+void Rc<T>::operator=(Rc &&other) {}
+
+template <typename T>
+Rc<T>::~Rc() {
+    if (--refs == 0)
+        delete data;
+}
+
+template <typename T>
+const T &Rc<T>::borrow() noexcept {
+    return *data;
+}
+
+template <typename T>
+T &Rc<T>::borrow_mut() noexcept {
+    return *data;
+}
+
+int main() {
+    std::cout << "Template" << std::endl;
+    Rc<int> a = Rc(10);
+    auto b = Rc(10);
+    b.borrow_mut()++;
+    std::cout << a.borrow() << std::endl;
+    std::cout << b.borrow() << std::endl;
+
+    a = b;
+}