commit test

ch22/IntegerMapping.cc

@@ -27,7 +27,7 @@ class Negate : public IntegerMapping {
 
 class Compose : public IntegerMapping {     
  public:
-  Compose(IntegerMapping &n1, IntegerMapping &n2) : m1(&n1), m2(&n2) {}
+  Compose(IntegerMapping *n1, IntegerMapping *n2) : m1(n1), m2(n2) {}
   int maps(int x) const {
     return m1->maps(m2->maps(x));
   }
@@ -47,3 +47,4 @@ int main(int argc, char **argv) {
   cout << weird(&c, 15, 16) << endl;
   return 0;
 }
+

ch23/reference_virtual.cc

@@ -22,7 +22,7 @@ class SecondClass : public FirstClass {
   void print1() {
     cout << "SecondClass::print1()" << endl;
   }
-  virtual void print2() {
+  void print2() {
     cout << "SecondClass::print2()" << endl;
   }
 };
@@ -32,7 +32,7 @@ class ThirdClass : public SecondClass {
   void print1() {
     cout << "ThirdClass::print1()" << endl;
   }
-  virtual void print2() {
+  void print2() {
     cout << "ThirdClass::print2()" << endl;
   }
 };

ch25/Internal_vector.cc

@@ -0,0 +1,140 @@
+#include <iostream>
+
+using namespace std;
+
+class InternalVector {     
+ public:
+  double *data;
+  int size;
+  int nbref;
+
+  InternalVector(double *d, int s) : data(new double[s]),
+                                     size(s), nbref(0) {
+    cout << " + Expensive allocation and copy" << endl;
+    for (int k = 0; k < s; k++) {
+      data[k] = d[k];
+    }
+  }
+
+  ~InternalVector() {
+    cout << " + Destruction" << endl;
+    delete[] data;
+  }
+
+  void release() {
+    if (--nbref == 0) {
+      delete this;
+    }
+  }
+
+  InternalVector *grab() {
+    nbref++;
+    return this;
+  }
+
+  InternalVector *own() {
+    if (nbref == 1) {
+      return this;
+    } else {
+      nbref--;
+      InternalVector *result = new InternalVector(data, size);
+      result->nbref++;
+      return result;
+    }
+  }
+};
+
+class Vector {     
+ public:
+  Vector();
+  Vector(double *d, int s);
+  Vector(const Vector &v);
+  ~Vector();
+  Vector & operator = (const Vector &v);
+  inline double get(int k) const;
+  inline void set(int k, double v);
+  inline int size() const;
+ private:
+  InternalVector *internal;
+};
+
+
+Vector::Vector() {
+  cout << " * Creating empty Vector" << endl;
+  internal = 0;
+}
+
+Vector::Vector(double *d, int s) {
+  cout << " * Creating Vector" << endl;
+  internal = new InternalVector(d, s);
+  internal->grab();
+}
+
+Vector::Vector(const Vector &v) {
+  cout << " * Coping Vector" << endl;
+  if (v.internal) {
+    internal = v.internal->grab();
+  } else {
+    internal = 0;
+  }
+}
+
+Vector::~Vector() {
+  cout << " * Destorying Vector" << endl;
+  if (internal) {
+    internal->release();
+  }
+}
+
+Vector & Vector::operator = (const Vector &v) {
+  cout << " * Assigning Vector from Vector" << endl;
+  if (this != &v) {
+    if (internal) {
+      internal->release();
+      internal = v.internal->grab();
+    }
+  }
+}
+
+inline double Vector::get(int k) const {
+  return internal->data[k];
+}
+
+inline void Vector::set(int k, double v) {
+  if (v != internal->data[k]) {
+    internal = internal->own();
+    internal->data[k] = v;
+  }
+}
+
+inline int Vector::size() const {
+  return internal->size;
+}
+
+double sum(Vector v) {
+  cout << "Entering sum()" << endl;
+  double s = 0;
+  for (int i = 0; i < v.size(); i++) {
+	s += v.get(i);
+  }
+  cout << "Leaving sum()" << endl;
+  return s;
+}
+
+int main(int argc, char **argv) {
+  cout << "Doing double a[] = {1, 2, 3, 4, 5, 6, 7};" << endl;
+  double a[] = {1, 2, 3, 4, 5, 6, 7};
+  cout << "DOING Vector v(a, sizeof(a)/sizeof(double));" << endl;
+  Vector v(a, sizeof(a)/sizeof(double));
+  cout << "DING Vector w;" << endl;
+  Vector w;
+  cout << "DOING w = v;" << endl;
+  w = v;
+  cout << "DOING cout << sum(v) << \"\\n\";" << endl;
+  cout << sum(v) << endl;
+  cout << "DOING w.set(3, 2.1);" << endl;
+  w.set(3, 2.1);
+  cout << "FINISHED" << endl;
+
+  return 0;
+}

ch26/e1.cc

@@ -0,0 +1,13 @@
+#include <iostream>
+#include <string>
+
+using namespace std;
+
+int main(int argc, char **argv) {
+  string s = "What a beautiful weather!!!";
+  string t;
+  t = s;
+  std::cout << t << std::endl;
+
+  return 0;
+}

ch26/e2.cc

@@ -0,0 +1,25 @@
+#include <iostream>
+#include <string>
+
+using namespace std;
+
+void something(string s) {
+  cout << "s = [" << s << "]" << endl;
+  s[0] = 'X';
+  cout << "s = [" << s << "]" << endl;
+}
+
+int main(int argc, char **argv) {
+  string s1 = "University";
+  string s2 = " of ";
+  string s3(" Chicago");
+  string s4;
+  s4 = s1 + s2;
+  s4 += s3;
+  cout << s4 << endl;
+  s1 = s4.substr(11, 2);
+  cout << s1 << endl;
+  something(s1);
+  cout << s1 << endl;
+  return 0;
+}

ch26/e3.cc

@@ -0,0 +1,25 @@
+class IntIterator {     
+ public:
+  virtual bool hasNext() = 0;
+  virtual int next() = 0;
+};
+
+class SmallIterator : public IntIterator {     
+ public:
+  SmallIterator() : n(0) {}
+  SmallIterator(int aa) : a(aa), n(1) {}
+  SmallIterator(int bb, int aa) :a(aa), b(bb), n(2) {}
+  bool hasNext() {
+    return n > 0;
+  }
+  int next() {
+    n--;
+    if (n == 1) {
+      return b;
+    } else if (n == 0) {
+      return a;
+    }
+  }
+ private:
+  int a, b, n;
+};