Import all this stuff into a single repo called Serenity.

AK/RetainPtr.h

@@ -0,0 +1,128 @@
+#pragma once
+
+#include <cstddef>
+#include <utility>
+
+namespace AK {
+
+template<typename T>
+inline void retainIfNotNull(T* ptr)
+{
+    if (ptr)
+        ptr->retain();
+}
+
+template<typename T>
+inline void releaseIfNotNull(T* ptr)
+{
+    if (ptr)
+        ptr->release();
+}
+
+template<typename T>
+class RetainPtr {
+public:
+    enum AdoptTag { Adopt };
+
+    RetainPtr() { }
+    RetainPtr(const T* ptr) : m_ptr(const_cast<T*>(ptr)) { retainIfNotNull(m_ptr); }
+    RetainPtr(T* ptr) : m_ptr(ptr) { retainIfNotNull(m_ptr); }
+    RetainPtr(T& object) : m_ptr(&object) { m_ptr->retain(); }
+    RetainPtr(AdoptTag, T& object) : m_ptr(&object) { }
+    RetainPtr(RetainPtr&& other) : m_ptr(other.leakRef()) { }
+    template<typename U> RetainPtr(RetainPtr<U>&& other) : m_ptr(static_cast<T*>(other.leakRef())) { }
+    ~RetainPtr() { clear(); }
+    RetainPtr(std::nullptr_t) { }
+
+    RetainPtr& operator=(RetainPtr&& other)
+    {
+        if (this != &other) {
+            releaseIfNotNull(m_ptr);
+            m_ptr = other.leakRef();
+        }
+        return *this;
+    }
+
+    template<typename U>
+    RetainPtr& operator=(RetainPtr<U>&& other)
+    {
+        if (this != static_cast<void*>(&other)) {
+            releaseIfNotNull(m_ptr);
+            m_ptr = other.leakRef();
+        }
+        return *this;
+    }
+
+    RetainPtr& operator=(T* ptr)
+    {
+        if (m_ptr != ptr)
+            releaseIfNotNull(m_ptr);
+        m_ptr = ptr;
+        retainIfNotNull(m_ptr);
+        return *this;
+    }
+
+    RetainPtr& operator=(T& object)
+    {
+        if (m_ptr != &object)
+            releaseIfNotNull(m_ptr);
+        m_ptr = &object;
+        retainIfNotNull(m_ptr);
+        return *this;
+    }
+
+    RetainPtr& operator=(std::nullptr_t)
+    {
+        clear();
+        return *this;
+    }
+
+    RetainPtr copyRef() const
+    {
+        return RetainPtr(m_ptr);
+    }
+
+    void clear()
+    {
+        releaseIfNotNull(m_ptr);
+        m_ptr = nullptr;
+    }
+
+    bool operator!() const { return !m_ptr; }
+
+    typedef T* RetainPtr::*UnspecifiedBoolType;
+    operator UnspecifiedBoolType() const { return m_ptr ? &RetainPtr::m_ptr : nullptr; }
+
+    T* leakRef()
+    {
+        T* leakedPtr = m_ptr;
+        m_ptr = nullptr;
+        return leakedPtr;
+    }
+
+    T* ptr() { return m_ptr; }
+    const T* ptr() const { return m_ptr; }
+
+    T* operator->() { return m_ptr; }
+    const T* operator->() const { return m_ptr; }
+
+    T& operator*() { return *m_ptr; }
+    const T& operator*() const { return *m_ptr; }
+
+    operator bool() { return !!m_ptr; }
+
+private:
+    T* m_ptr = nullptr;
+};
+
+template<typename T>
+inline RetainPtr<T> adopt(T& object)
+{
+    return RetainPtr<T>(RetainPtr<T>::Adopt, object);
+}
+
+}
+
+using AK::RetainPtr;
+using AK::adopt;
+