update chapter 15

Author: ShiqiYu

.gitignore

@@ -1,5 +1,3 @@
 *.out
 settings.json
-week01/~$Lecture01.pptx
-week02/~$Lecture02.pptx
-week03/~$Lecture03.pptx
+.DS_Store

week15/Lecture15.pptx

@@ -1,21 +1,13 @@
 #include <iostream>
 using namespace std;
 
-void increase(const int * pn)
-{
-    int * pi;
-    pi = const_cast<int *>(pn);
-    (*pi)++; // undefined behavior
-}
-
-
 int main()
 {
     int value1 = 100;
     const int value2 = 200;
     cout << "value1 = " << value1 << endl;
     cout << "value2 = " << value2 << endl;
-    
+
     int * pv1 = const_cast<int *>(&value1);
     int * pv2 = const_cast<int *>(&value2);
 
@@ -25,12 +17,14 @@ int main()
     cout << "value1 = " << value1 << endl;
     cout << "value2 = " << value2 << endl;
 
-    int v2 = const_cast<int&>(value2);
+    int& v2 = const_cast<int&>(value2);
     v2++;
     cout << "value2 = " << value2 << endl;
 
-    // cout << "*pv2 = " << (*pv2) << endl;
-    // cout << "v2 = " << v2 << endl;
+    cout << "*pv2 = " << (*pv2) << endl;
+    cout << "v2 = " << v2 << endl;
 
-    return 0;
+   return 0;
 }
+
+

week15/examples/const_cast.cpp

@@ -20,9 +20,9 @@ class Mat
 
 int main()
 {
-    Mat image(DataType::TYPE8U);
+    Mat image(TYPE8U);
 
-    if (image.getType() == DataType::TYPE8U)
+    if (image.getType() == TYPE8U)
         std::cout << "This is an 8U matrix." << std::endl;
 	else
         std::cout << "I am not an 8U matrix." << std::endl;

week15/examples/nested-enum1.cpp

@@ -0,0 +1,14 @@
+#include <iostream>
+using namespace std;
+
+int main()
+{
+    int i = 18;
+    float * p1 = reinterpret_cast<float *>(i); // static_cast will fail
+    int * p2 = reinterpret_cast<int*>(p1);
+
+    printf("p1=%p\n", p1);
+    printf("p2=%p\n", p2);
+
+    return 0;
+}

week15/examples/reinterpret_cast.cpp

@@ -29,9 +29,9 @@ int main()
     cout << person.getInfo() << endl;
     cout << ps->getInfo() << endl; // danger if getInfo is not virtual
 
-    // ps = dynamic_cast<Student*>(&person);
-    // printf("address = %p\n", ps);
-    // pp = dynamic_cast<Person*>(&student);
-    // printf("address = %p\n", pp);
+    ps = dynamic_cast<Student*>(&person);
+    printf("address = %p\n", ps);
+    pp = dynamic_cast<Person*>(&student);
+    printf("address = %p\n", pp);
     return 0;
 }