From 4fa30d56305c51fa9db5e5960806ce93095192aa Mon Sep 17 00:00:00 2001
From: Simon Rozman <simon@rozman.si>
Date: Mon, 30 Sep 2024 09:40:19 +0200
Subject: [PATCH] memory: add get_ptr

This was migrated from WinStd being platform independent.

Signed-off-by: Simon Rozman <simon@rozman.si>
---
 include/stdex/memory.hpp | 154 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 154 insertions(+)

diff --git a/include/stdex/memory.hpp b/include/stdex/memory.hpp
index 1041da3ce..97c6f05b7 100644
--- a/include/stdex/memory.hpp
+++ b/include/stdex/memory.hpp
@@ -139,6 +139,160 @@ namespace stdex
 	public:
 		unsigned char m_data[N]; ///< BLOB data
 	};
+
+	///
+	/// Helper class for returning pointers to std::unique_ptr
+	///
+	template <typename T, typename D>
+	class ref_unique_ptr
+	{
+	public:
+		///
+		/// Takes ownership of the pointer
+		///
+		/// \param[in,out] owner  Object to attach helper to
+		///
+		ref_unique_ptr(_Inout_ std::unique_ptr<T, D> &owner) :
+			m_own(owner),
+			m_ptr(owner.release())
+		{}
+
+		///
+		/// Moves object
+		///
+		/// \param[in,out] other  Source object
+		///
+		ref_unique_ptr(_Inout_ ref_unique_ptr<T, D> &&other) :
+			m_own(other.m_own),
+			m_ptr(other.m_ptr)
+		{
+			other.m_ptr = nullptr;
+		}
+
+		///
+		/// Returns ownership of the pointer
+		///
+		~ref_unique_ptr()
+		{
+			if (m_ptr != nullptr)
+				m_own.reset(m_ptr);
+		}
+
+		///
+		/// Operator for pointer-to-pointer parameters by value use-cases.
+		///
+		/// \return Pointer to the pointer
+		///
+		operator T**()
+		{
+			return &m_ptr;
+		}
+
+		///
+		/// Operator for reverence-to-pointer parameters by value use-cases.
+		///
+		/// \return Reference to the pointer
+		///
+		operator T*&()
+		{
+			return m_ptr;
+		}
+
+	protected:
+		std::unique_ptr<T, D> &m_own; ///< Original owner of the pointer
+		T *m_ptr;                     ///< Pointer
+	};
+
+	///
+	/// Helper function template for returning pointers to std::unique_ptr
+	///
+	/// \param[in,out] owner  Original owner of the pointer
+	///
+	/// \returns A helper wrapper class to handle returning a reference to the pointer
+	///
+	template<class T, class D>
+	ref_unique_ptr<T, D> get_ptr(_Inout_ std::unique_ptr<T, D> &owner) noexcept
+	{
+		return ref_unique_ptr<T, D>(owner);
+	}
+
+	///
+	/// Helper class for returning pointers to std::unique_ptr
+	/// (specialization for arrays)
+	///
+	template<typename T, typename D>
+	class ref_unique_ptr<T[], D>
+	{
+	public:
+		///
+		/// Takes ownership of the pointer
+		///
+		/// \param[in,out] owner  Object to attach helper to
+		///
+		ref_unique_ptr(_Inout_ std::unique_ptr<T[], D> &owner) noexcept :
+			m_own(owner),
+			m_ptr(owner.release())
+		{}
+
+		///
+		/// Moves object
+		///
+		/// \param[in,out] other  Source object
+		///
+		ref_unique_ptr(_Inout_ ref_unique_ptr<T[], D> &&other) :
+			m_own(other.m_own),
+			m_ptr(other.m_ptr)
+		{
+			other.m_ptr = nullptr;
+		}
+
+		///
+		/// Returns ownership of the pointer
+		///
+		virtual ~ref_unique_ptr()
+		{
+			if (m_ptr != nullptr)
+				m_own.reset(m_ptr);
+		}
+
+		///
+		/// Operator for pointer-to-pointer parameters by value use-cases.
+		///
+		/// \return Pointer to the pointer
+		///
+		operator T**() noexcept
+		{
+			return &m_ptr;
+		}
+
+		///
+		/// Operator for reverence-to-pointer parameters by value use-cases.
+		///
+		/// \return Reference to the pointer
+		///
+		operator T*&()
+		{
+			return m_ptr;
+		}
+
+	protected:
+		std::unique_ptr<T[], D> &m_own; ///< Original owner of the pointer
+		T *m_ptr;                       ///< Pointer
+	};
+
+	///
+	/// Helper function template for returning pointers to std::unique_ptr
+	/// (specialization for arrays)
+	///
+	/// \param[in,out] owner  Original owner of the pointer
+	///
+	/// \returns A helper wrapper class to handle returning a reference to the pointer
+	///
+	template<class T, class D>
+	ref_unique_ptr<T[], D> get_ptr(_Inout_ std::unique_ptr<T[], D>& owner) noexcept
+	{
+		return ref_unique_ptr<T[], D>(owner);
+	}
 }
 
 #if defined(__GNUC__)