Merge branch 'add-some-oo-exercise' into 'master'

Add some oo exercise

See merge request sponce/cpluspluscourse!15

code/ExercisesCheatSheet.md

@@ -20,6 +20,10 @@ poly->computePerimeter();
 ```
 and check what is called, in regular and virtual method case
 
+### modern_oo
+
+Insert one `= delete`, one `= default` and one `override`.
+
 ### virtual_inheritance
 First create a TextBox and try to call draw.
 There will be an error that the member is ambiguous, due to multiple inheritance.

code/modern_oo/README.md

+
+## Prerequisites
+
+* know about classes in ancient C++
+
+## Instructions
+
+* insert one `= delete`, one `= default` and one `override`.

code/modern_oo/particles.cpp

+#include <cstdlib> // pour std::rand()
+#include <iostream>
+#include <string>
+
+class Particle
+ {
+  public  :
+    Particle( double mass ) : mass_(mass) {}
+    double mass() { return mass_ ; }
+    virtual std::string name() { return "Particle" ; }
+    virtual ~Particle() {}
+  private  :
+    Particle( const Particle & ) ; // non copiable
+    double mass_ ;
+ } ;
+
+class ChargedParticle : public Particle
+ {
+  public  :
+    ChargedParticle( double mass, double charge )
+     : Particle(mass), charge_(charge) {}
+    double charge() { return charge_ ; }
+    virtual std::string name() { return "ChargedParticle" ; }
+  private  :
+    double charge_ ;
+ } ;
+
+void print( Particle & p  )
+ {
+  std::cout << p.name() << std::endl ;          
+  std::cout << "  mass = " << p.mass() << std::endl ;         
+ }
+
+int main()
+ {
+  for ( int i = 0 ; i < 5 ; ++i )
+   {
+    if ( std::rand() < (0.5 *  double(RAND_MAX)) )
+     {
+      Particle p(2) ;
+      print(p) ;
+     }
+    else
+     {
+      ChargedParticle p(1,1) ;
+      print(p) ;
+      std::cout << "  charge = " << p.charge() << std::endl ;         
+     }
+   }
+ }
+ 
\ No newline at end of file

code/modern_oo/solution/particles.sol.cpp

+#include <cstdlib> // pour std::rand()
+#include <iostream>
+#include <string>
+
+class Particle
+ {
+  public  :
+    Particle( double mass ) : mass_(mass) {}
+    Particle( const Particle & ) = delete ;
+    virtual ~Particle() = default ;
+    double mass() { return mass_ ; }
+    virtual std::string name() { return "Particle" ; }
+  private  :
+    double mass_ ;
+ } ;
+
+class ChargedParticle : public Particle
+ {
+  public  :
+    ChargedParticle( double mass, double charge )
+     : Particle(mass), charge_(charge) {}
+    double charge() { return charge_ ; }
+    std::string name() override { return "ChargedParticle" ; }
+  private  :
+    double charge_ = 0.0 ;
+ } ;
+
+void display( Particle & p  )
+ {
+  std::cout << p.name() << std::endl ;          
+  std::cout << "  mass = " << p.mass() << std::endl ;         
+ }
+
+int main()
+ {
+  for ( int i = 0 ; i < 5 ; ++i )
+   {
+    if ( std::rand() < (0.5 *  double(RAND_MAX)) )
+     {
+      Particle p(2) ;
+      display(p) ;
+     }
+    else
+     {
+      ChargedParticle p(1,1) ;
+      display(p) ;
+      std::cout << "  charge = " << p.charge() << std::endl ;         
+     }
+   }
+ }
\ No newline at end of file

code/polymorphism/README.md

 ## Instructions for the "polymorphism" exercise
 
+Step 1
 * look at the code
 * open `trypoly.cpp`
 * create a Pentagon, call its `perimeter` method
@@ -10,6 +11,8 @@
 ```
 * create an Hexagon, call its `perimeter` method
 * recompile and check what happens
+
+Step 2
 * create an Hexagon, call its parent’s `perimeter` method
 * recompile and check again
 * retry with virtual methods

code/virtual_inheritance/README.md

 
 ## Instructions
 
+Step 1
 * look at the code
 * open `test.cpp`
 * create a `TextBox` and call `draw`
 * Fix the code to call both draws by using types
+
+Step 2
 * retry with virtual inheritance
\ No newline at end of file