c++: rule of five

rule-of-five.cpp

@@ -0,0 +1,46 @@
+class rule_of_five
+{
+    char* cstring; // raw pointer used as a handle to a dynamically-allocated memory block
+ public:
+    rule_of_five(const char* s = "")
+    : cstring(nullptr)
+    {
+        if (s) {
+            std::size_t n = std::strlen(s) + 1;
+            cstring = new char[n];      // allocate
+            std::memcpy(cstring, s, n); // populate
+        }
+    }
+
+    ~rule_of_five()
+    {
+        delete[] cstring;  // deallocate
+    }
+
+    rule_of_five(const rule_of_five& other) // copy constructor
+    : rule_of_five(other.cstring)
+    {}
+
+    rule_of_five(rule_of_five&& other) noexcept // move constructor
+    : cstring(std::exchange(other.cstring, nullptr))
+    {}
+
+    rule_of_five& operator=(const rule_of_five& other) // copy assignment
+    {
+         return *this = rule_of_five(other);
+    }
+
+    rule_of_five& operator=(rule_of_five&& other) noexcept // move assignment
+    {
+        std::swap(cstring, other.cstring);
+        return *this;
+    }
+
+// alternatively, replace both assignment operators with
+//  rule_of_five& operator=(rule_of_five other) noexcept
+//  {
+//      std::swap(cstring, other.cstring);
+//      return *this;
+//  }
+};
+