merge checkpoint 2 - functional merge without q4_0_4_4 (need regen shaders)

include/vulkan/slang/slang-com-ptr.h

@@ -0,0 +1,160 @@
+#ifndef SLANG_COM_PTR_H
+#define SLANG_COM_PTR_H
+
+#include "slang-com-helper.h"
+
+#include <assert.h>
+#include <cstddef>
+
+namespace Slang {
+
+/*! \brief ComPtr is a simple smart pointer that manages types which implement COM based interfaces.
+\details A class that implements a COM, must derive from the IUnknown interface or a type that matches
+it's layout exactly (such as ISlangUnknown). Trying to use this template with a class that doesn't follow
+these rules, will lead to undefined behavior.
+This is a 'strong' pointer type, and will AddRef when a non null pointer is set and Release when the pointer
+leaves scope.
+Using 'detach' allows a pointer to be removed from the management of the ComPtr.
+To set the smart pointer to null, there is the method setNull, or alternatively just assign SLANG_NULL/nullptr.
+
+One edge case using the template is that sometimes you want access as a pointer to a pointer. Sometimes this
+is to write into the smart pointer, other times to pass as an array. To handle these different behaviors
+there are the methods readRef and writeRef, which are used instead of the & (ref) operator. For example
+
+\code
+Void doSomething(ID3D12Resource** resources, IndexT numResources);
+// ...
+ComPtr<ID3D12Resource> resources[3];
+doSomething(resources[0].readRef(), SLANG_COUNT_OF(resource));
+\endcode
+
+A more common scenario writing to the pointer
+
+\code
+IUnknown* unk = ...;
+
+ComPtr<ID3D12Resource> resource;
+Result res = unk->QueryInterface(resource.writeRef());
+\endcode
+*/
+
+// Enum to force initializing as an attach (without adding a reference)
+enum InitAttach
+{
+    INIT_ATTACH
+};
+
+template <class T>
+class ComPtr
+{
+public:
+	typedef T Type;
+	typedef ComPtr ThisType;
+	typedef ISlangUnknown* Ptr;
+
+		/// Constructors
+		/// Default Ctor. Sets to nullptr
+	SLANG_FORCE_INLINE ComPtr() :m_ptr(nullptr) {}
+    SLANG_FORCE_INLINE ComPtr(std::nullptr_t) : m_ptr(nullptr) {}
+		/// Sets, and ref counts.
+	SLANG_FORCE_INLINE explicit ComPtr(T* ptr) :m_ptr(ptr) { if (ptr) ((Ptr)ptr)->addRef(); }
+		/// The copy ctor
+	SLANG_FORCE_INLINE ComPtr(const ThisType& rhs) : m_ptr(rhs.m_ptr) { if (m_ptr) ((Ptr)m_ptr)->addRef(); }
+
+        /// Ctor without adding to ref count.
+    SLANG_FORCE_INLINE explicit ComPtr(InitAttach, T* ptr) :m_ptr(ptr) { }
+        /// Ctor without adding to ref count
+    SLANG_FORCE_INLINE ComPtr(InitAttach, const ThisType& rhs) : m_ptr(rhs.m_ptr) { }
+
+#ifdef SLANG_HAS_MOVE_SEMANTICS
+		/// Move Ctor
+	SLANG_FORCE_INLINE ComPtr(ThisType&& rhs) : m_ptr(rhs.m_ptr) { rhs.m_ptr = nullptr; }
+		/// Move assign
+	SLANG_FORCE_INLINE ComPtr& operator=(ThisType&& rhs) { T* swap = m_ptr; m_ptr = rhs.m_ptr; rhs.m_ptr = swap; return *this; }
+#endif
+
+	/// Destructor releases the pointer, assuming it is set
+	SLANG_FORCE_INLINE ~ComPtr() { if (m_ptr) ((Ptr)m_ptr)->release(); }
+
+	// !!! Operators !!!
+
+	  /// Returns the dumb pointer
+	SLANG_FORCE_INLINE operator T *() const { return m_ptr; }
+
+	SLANG_FORCE_INLINE T& operator*() { return *m_ptr; }
+		/// For making method invocations through the smart pointer work through the dumb pointer
+	SLANG_FORCE_INLINE T* operator->() const { return m_ptr; }
+
+		/// Assign
+	SLANG_FORCE_INLINE const ThisType &operator=(const ThisType& rhs);
+		/// Assign from dumb ptr
+	SLANG_FORCE_INLINE T* operator=(T* in);
+
+		/// Get the pointer and don't ref
+	SLANG_FORCE_INLINE T* get() const { return m_ptr; }
+		/// Release a contained nullptr pointer if set
+	SLANG_FORCE_INLINE void setNull();
+
+		/// Detach
+	SLANG_FORCE_INLINE T* detach() { T* ptr = m_ptr; m_ptr = nullptr; return ptr; }
+		/// Set to a pointer without changing the ref count
+	SLANG_FORCE_INLINE void attach(T* in) { m_ptr = in; }
+
+		/// Get ready for writing (nulls contents)
+	SLANG_FORCE_INLINE T** writeRef() { setNull(); return &m_ptr; }
+		/// Get for read access
+	SLANG_FORCE_INLINE T*const* readRef() const { return &m_ptr; }
+
+		/// Swap
+	void swap(ThisType& rhs);
+
+protected:
+	/// Gets the address of the dumb pointer.
+    // Disabled: use writeRef and readRef to get a reference based on usage.
+#ifndef SLANG_COM_PTR_ENABLE_REF_OPERATOR
+	SLANG_FORCE_INLINE T** operator&() = delete;
+#endif
+
+	T* m_ptr;
+};
+
+//----------------------------------------------------------------------------
+template <typename T>
+void ComPtr<T>::setNull()
+{
+	if (m_ptr)
+	{
+		((Ptr)m_ptr)->release();
+		m_ptr = nullptr;
+	}
+}
+//----------------------------------------------------------------------------
+template <typename T>
+const ComPtr<T>& ComPtr<T>::operator=(const ThisType& rhs)
+{
+	if (rhs.m_ptr) ((Ptr)rhs.m_ptr)->addRef();
+	if (m_ptr) ((Ptr)m_ptr)->release();
+	m_ptr = rhs.m_ptr;
+	return *this;
+}
+//----------------------------------------------------------------------------
+template <typename T>
+T* ComPtr<T>::operator=(T* ptr)
+{
+	if (ptr) ((Ptr)ptr)->addRef();
+	if (m_ptr) ((Ptr)m_ptr)->release();
+	m_ptr = ptr;
+	return m_ptr;
+}
+//----------------------------------------------------------------------------
+template <typename T>
+void ComPtr<T>::swap(ThisType& rhs)
+{
+	T* tmp = m_ptr;
+	m_ptr = rhs.m_ptr;
+	rhs.m_ptr = tmp;
+}
+
+} // namespace Slang
+
+#endif // SLANG_COM_PTR_H