added some simple pointer koans

Author: torbjoernk

headers/koan05_pointers.hpp

@@ -33,7 +33,7 @@ class Koan05_pointers : Koan
 {
   private:
     KoanHandler *status;                //!
-    static const int num_tests = 1;     //!
+    static const int num_tests = 4;     //!
 
   public:
     /**
@@ -51,7 +51,10 @@ class Koan05_pointers : Koan
      *
      */
     void run() {
-      status->eval_koan( *this, static_cast<void ( Koan:: * )()>( &Koan05_pointers::a_sample_koan ) );
+      status->eval_koan( *this, static_cast<void ( Koan:: * )()>( &Koan05_pointers::they_are_just_variables ) );
+      status->eval_koan( *this, static_cast<void ( Koan:: * )()>( &Koan05_pointers::they_are_really_just_variables ) );
+      status->eval_koan( *this, static_cast<void ( Koan:: * )()>( &Koan05_pointers::they_have_power ) );
+      status->eval_koan( *this, static_cast<void ( Koan:: * )()>( &Koan05_pointers::they_are_not_almighty ) );
 
       status->episode_done( "fifth" );
     }
@@ -65,7 +68,10 @@ class Koan05_pointers : Koan
 
   private:
     // REMARK: Do not forget to increase this.num_tests when you add another koan
-    void a_sample_koan();
+    void they_are_just_variables();
+    void they_are_really_just_variables();
+    void they_have_power();
+    void they_are_not_almighty();
 };
 
 #endif // KOAN05_POINTERS_HPP

helper.hpp

@@ -33,5 +33,6 @@
 
 #define FILL_THE_NUMBER_IN 0
 #define FILL_THE_CHAR_IN ' '
+#define THIS_IS_NOT_NULL NULL
 
 // EOF

koans/koan05_pointers.cpp

@@ -25,10 +25,48 @@
 
 #include "../headers/koan05_pointers.hpp"
 
-void Koan05_pointers::a_sample_koan()
+void Koan05_pointers::they_are_just_variables()
 {
-  bool test = false;
-  ASSERT_EQUAL( test, true );
+  int an_int = 42;
+  int *pointer_to_an_int = &an_int;
+  ASSERT_EQUAL( *pointer_to_an_int, FILL_THE_NUMBER_IN );
+  ASSERT_EQUAL( pointer_to_an_int, THIS_IS_NOT_NULL );
+}
+
+void Koan05_pointers::they_are_really_just_variables()
+{
+  int an_int = 42;
+  int another_int = 21;
+  int *pointer_to_an_int = &an_int;
+  ASSERT_EQUAL( *pointer_to_an_int, FILL_THE_NUMBER_IN );
+  ASSERT_EQUAL( pointer_to_an_int, THIS_IS_NOT_NULL );
+  pointer_to_an_int = &another_int;
+  ASSERT_EQUAL( *pointer_to_an_int, FILL_THE_NUMBER_IN );
+  ASSERT_EQUAL( pointer_to_an_int, THIS_IS_NOT_NULL );
+}
+
+void Koan05_pointers::they_have_power()
+{
+  int an_int = 42;
+  int *powerful_pointer = &an_int;
+  ASSERT_EQUAL( *powerful_pointer, FILL_THE_NUMBER_IN );
+  ASSERT_EQUAL( powerful_pointer, THIS_IS_NOT_NULL );
+  *powerful_pointer = 21;
+  ASSERT_EQUAL( an_int, FILL_THE_NUMBER_IN );
+  ASSERT_EQUAL( powerful_pointer, THIS_IS_NOT_NULL );
+}
+
+void Koan05_pointers::they_are_not_almighty()
+{
+  const int an_int = 42;
+  const int *wannabe_powerful = &an_int;
+  ASSERT_EQUAL( *wannabe_powerful, FILL_THE_NUMBER_IN );
+  ASSERT_EQUAL( wannabe_powerful, THIS_IS_NOT_NULL );
+  // Will this work? Think about it!
+  // What do you need to change to make it work?
+//   *wannabe_powerful = 21;
+  ASSERT_EQUAL( an_int, FILL_THE_NUMBER_IN );
+  ASSERT_EQUAL( wannabe_powerful, THIS_IS_NOT_NULL );
 }
 
 // EOF