Doc: Modernize QSharedDataPointer Example for Rule of Compliance

Replaced the manually defined copy constructor with = default to
improve clarity and maintainability.Added a default copy assignment
operator to ensure consistency,as copy constructor and copy
assignment should be defined as a pair.Also included defaulted move
constructor and move assignment operator in accordance with the rule
of 6,ensuring the example is modern,complete,and suitable for
educational purposes.

Fixes: QTBUG-111392
Change-Id: Ia7cfccfc46182d8d9102868fc93dc0ebd9649a32
Reviewed-by: Axel Spoerl <axel.spoerl@qt.io>

src/corelib/doc/snippets/sharedemployee/employee.h

@@ -6,15 +6,16 @@
 
 //! [0]
 #include <QSharedData>
+#include <QSharedDataPointer>
 #include <QString>
 
 class EmployeeData : public QSharedData
 {
-  public:
-    EmployeeData() : id(-1) { }
+public:
+    EmployeeData() : id(-1) {}
     EmployeeData(const EmployeeData &other)
-        : QSharedData(other), id(other.id), name(other.name) { }
-    ~EmployeeData() { }
+        : QSharedData(other), id(other.id), name(other.name) {}
+    ~EmployeeData() = default;
 
     int id;
     QString name;
@@ -22,34 +23,38 @@ class EmployeeData : public QSharedData
 
 class Employee
 {
-  public:
-//! [1]
+public:
+    //! [1]
     Employee() { d = new EmployeeData; }
-//! [1] //! [2]
+    //! [1] //! [2]
     Employee(int id, const QString &name) {
         d = new EmployeeData;
         setId(id);
         setName(name);
     }
-//! [2] //! [7]
-    Employee(const Employee &other)
-          : d (other.d)
-    {
-    }
-//! [7]
-//! [3]
+    //! [2] //! [7]
+    Employee(const Employee &other) = default;
+    Employee &operator=(const Employee &other) = default;
+
+    Employee(Employee &&other) = default;
+    Employee &operator=(Employee &&other) = default;
+
+    ~Employee() = default;
+
+    //! [7]
+    //! [3]
     void setId(int id) { d->id = id; }
-//! [3] //! [4]
+    //! [3] //! [4]
     void setName(const QString &name) { d->name = name; }
-//! [4]
+    //! [4]
 
-//! [5]
+    //! [5]
     int id() const { return d->id; }
-//! [5] //! [6]
+    //! [5] //! [6]
     QString name() const { return d->name; }
-//! [6]
+    //! [6]
 
-  private:
+private:
     QSharedDataPointer<EmployeeData> d;
 };
 //! [0]