From e46c0b647737b5b398270175ee6d7b0115c42a86 Mon Sep 17 00:00:00 2001
From: roker <roker@pep-project.org>
Date: Fri, 7 May 2021 17:34:33 +0200
Subject: [PATCH] generic wrapper for several C datatypes.

---
 src/wrapper.hh | 85 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 85 insertions(+)
 create mode 100644 src/wrapper.hh

diff --git a/src/wrapper.hh b/src/wrapper.hh
new file mode 100644
index 0000000..5068797
--- /dev/null
+++ b/src/wrapper.hh
@@ -0,0 +1,85 @@
+// This file is under GNU General Public License 3.0
+// see LICENSE.txt
+
+#ifndef PEP_DATATYPES_WRAPPER_HH
+#define PEP_DATATYPES_WRAPPER_HH
+
+namespace pEp
+{
+
+template<class T>
+class Wrapper
+{
+public:
+    template<class... Args>
+    Wrapper(Args... args) : value{ _new(args...) } {}
+    
+    // no implicit copying... (yet?)
+    Wrapper(const Wrapper<T>&) = delete;
+    void operator=(const Wrapper<T>&) = delete;
+    
+    // must be implemented separately for each T
+    Wrapper(Wrapper<T>&& victim);
+    Wrapper<T>& operator=(Wrapper<T>&& victim);
+    
+    ~Wrapper();
+
+    Wrapper<T> copy() const;
+
+private:
+    // must be defined for each wrapped type:
+    template<class... Args>
+    T* _new(Args...);
+
+    T value;
+};
+
+
+// many wrapped datatypes are pointers, we can generalize a lot for them:
+template<class T>
+class Wrapper<T*>
+{
+public:
+    Wrapper() : value{nullptr} {}
+
+    template<class... Args>
+    Wrapper(Args... args) : value{ _new(args...) } {}
+
+    // no implicit copying... (yet?)
+    Wrapper(const Wrapper<T*>&) = delete;
+    void operator=(const Wrapper<T*>&) = delete;
+    
+    // must be implemented separately for each T
+    Wrapper(Wrapper<T*>&& victim)
+    : value{ victim.value}
+    {
+        victim.value = nullptr;
+    }
+    
+    Wrapper<T*>&& operator=(Wrapper<T*>&& victim)
+    {
+        _free();
+        value = victim.value;
+        victim.value = nullptr;
+    }
+    
+    ~Wrapper()
+    {
+        _free();
+    }
+    
+
+private:
+    // must be defined for each wrapped type:
+    template<class... Args>
+    T* _new(Args...);
+    
+    void _free();
+
+    T* value;
+};
+
+
+} // end of namespace pEp
+
+#endif // PEP_DATATYPES_WRAPPER_HH