cc examples

15 files changed, 421 insertions, 0 deletions

diff --git a/c,cc/base_derived_vector.cc b/c,cc/base_derived_vector.cc
new file mode 100644
index 0000000..e20a43d
--- /dev/null
+++ b/c,cc/base_derived_vector.cc
@@ -0,0 +1,35 @@
+#include <iostream>
+#include <vector>
+
+class Base {
+public:
+  virtual void
+  f()
+  {
+      std::cout << "Base\n";
+  }
+};
+
+class Derived: public Base {
+public:
+  virtual void
+  f()
+  {
+      std::cout << "Derived\n";
+  }
+};
+
+int
+main()
+{
+  std::vector<Base> s;
+  Base a;
+  s.push_back(a);
+  Derived b;
+  s.push_back(b);
+  for (std::vector<Base>::iterator it = s.begin(); it != s.end(); ++it)
+    it->f();
+
+  return 0;
+}
+
diff --git a/c,cc/copy_struct.cc b/c,cc/copy_struct.cc
new file mode 100644
index 0000000..cb23b09
--- /dev/null
+++ b/c,cc/copy_struct.cc
@@ -0,0 +1,36 @@
+#include <iostream>
+#include <vector>
+
+using namespace std;
+
+struct C {
+  vector<int> i;
+};
+
+struct B {
+  C c;
+};
+
+struct A {
+  B b;
+};
+
+int
+main(void)
+{
+  A a;
+  B b;
+  C c;
+ 
+  c.i.push_back(23);
+  b.c = c;
+  a.b = b;
+
+  cout << a.b.c.i[0] << endl;
+
+  A x(a);
+  cout << x.b.c.i[0] << endl;
+
+  return 0;
+}
+
diff --git a/c,cc/delegate_iterator.cc b/c,cc/delegate_iterator.cc
new file mode 100644
index 0000000..c4e272e
--- /dev/null
+++ b/c,cc/delegate_iterator.cc
@@ -0,0 +1,32 @@
+#include <iostream>
+#include <vector>
+
+using namespace std;
+
+class A {
+  private:
+    typedef vector<int> Data;
+    Data data_;
+  public:
+    typedef Data::iterator iterator;
+    typedef const Data::iterator const_iterator;
+    iterator begin() { return data_.begin(); }
+    iterator end() { return data_.end(); }
+
+    void add(int i) {
+      data_.push_back(i);
+    }
+};
+
+int
+main(void)
+{
+  A a;
+  a.add(23);
+  for (A::iterator it = a.begin(); it != a.end(); it++) {
+    cout << *it << endl;
+  }
+
+  return 0;
+}
+
diff --git a/c,cc/derived.cc b/c,cc/derived.cc
new file mode 100644
index 0000000..809378a
--- /dev/null
+++ b/c,cc/derived.cc
@@ -0,0 +1,28 @@
+#include <iostream>
+#include <vector>
+
+using namespace std;
+
+struct Base {
+  virtual int
+  index() { return -1; };
+};
+
+struct D1 : public Base {
+  int idx = 1;
+
+  virtual int
+  index() { return idx; }
+};
+
+int
+main(void)
+{
+  vector<Base*> v;
+  D1* d = new D1;
+  v.push_back(d);
+  cout << v.back()->index() << endl;
+
+  return 0;
+}
+
diff --git a/c,cc/padding.cc b/c,cc/padding.cc
new file mode 100644
index 0000000..7ac9be7
--- /dev/null
+++ b/c,cc/padding.cc
@@ -0,0 +1,32 @@
+#include <iostream>
+#include <string>
+
+using namespace std;
+
+struct foo {
+    int  a;
+    string b;
+    string b1;
+    int  c;
+    string b2;
+    string b3;
+};
+
+struct bar {
+    int  a;
+    int  c;
+    string b;
+    string b1;
+    string b2;
+    string b3;
+};
+
+int
+main(void)
+{
+  cout << sizeof(foo) << endl;
+  cout << sizeof(bar) << endl;
+
+  return 0;
+}
+
diff --git a/c,cc/pairs_stringstream.cc b/c,cc/pairs_stringstream.cc
new file mode 100644
index 0000000..300d55e
--- /dev/null
+++ b/c,cc/pairs_stringstream.cc
@@ -0,0 +1,22 @@
+#include <iostream>
+#include <vector>
+#include <string>
+#include <sstream>
+
+using namespace std;
+
+int
+main(void)
+{
+  istringstream ss("ufllffrrf");
+  ss.seekg(1);
+  while (ss.good()) {
+    char prev, cur;
+    ss >> prev;
+    ss >> cur;
+    cout << prev << " " << cur << endl;
+  }
+  
+  return 0;
+}
+
diff --git a/c,cc/pointer_to_element.cc b/c,cc/pointer_to_element.cc
new file mode 100644
index 0000000..5a11919
--- /dev/null
+++ b/c,cc/pointer_to_element.cc
@@ -0,0 +1,19 @@
+#include <vector>
+#include <iostream>
+
+using namespace std;
+
+int
+main(void)
+{
+  vector<char> bla;
+  bla.reserve(2);
+  bla.push_back('a');
+  char* p = &bla.at(0);
+  cout << *p << endl;
+  bla.push_back('b');
+  cout << *p << endl;
+
+  return 0;
+}
+
diff --git a/c,cc/reset_stringstream.cc b/c,cc/reset_stringstream.cc
new file mode 100644
index 0000000..474f014
--- /dev/null
+++ b/c,cc/reset_stringstream.cc
@@ -0,0 +1,25 @@
+#include <string>
+#include <iostream>
+#include <sstream>
+
+using namespace std;
+
+int
+main(void)
+{
+  string s("X,1");
+  string t("1");
+  int i;
+  istringstream ss(s);
+  if (ss >> i) {
+    cout << i << endl;
+  } else {
+    ss.clear();
+    string buf;
+    while(ss.good() && getline(ss,buf,','))
+      cout << buf << endl;
+  }
+
+  return 0;
+}
+
diff --git a/c,cc/reuse_stringstream.cc b/c,cc/reuse_stringstream.cc
new file mode 100644
index 0000000..f214544
--- /dev/null
+++ b/c,cc/reuse_stringstream.cc
@@ -0,0 +1,23 @@
+#include <sstream>
+#include <string>
+#include <iostream>
+
+using namespace std;
+
+int
+main(void)
+{
+  ostringstream ss;
+  for (int i = 0; i < 5; i++) {
+    ss.str(string()); 
+    ss << "asdf";
+    ss << i;
+    ss << i;
+    ss << i;
+    ss << i;
+    cout << ss.str() << endl;
+  }
+
+  return 0;
+}
+
diff --git a/c,cc/self_referencing_struct.cc b/c,cc/self_referencing_struct.cc
new file mode 100644
index 0000000..c084164
--- /dev/null
+++ b/c,cc/self_referencing_struct.cc
@@ -0,0 +1,19 @@
+#include <iostream>
+#include <vector>
+
+using namespace std;
+
+struct S {
+  int m;
+  vector<S> v;
+};
+
+int
+main(void)
+{
+  S a;
+  S b;
+  a.v.push_back(b);
+  return 0;
+}
+
diff --git a/c,cc/shared_ptr.cc b/c,cc/shared_ptr.cc
new file mode 100644
index 0000000..4fb158e
--- /dev/null
+++ b/c,cc/shared_ptr.cc
@@ -0,0 +1,31 @@
+#include <iostream>
+#include <memory>
+
+using namespace std;
+
+struct B {
+  B(int i) : m(i) {}
+  int m;
+};
+
+struct A {
+  shared_ptr<B> b;
+};
+
+int
+main(void)
+{
+  shared_ptr<B> x(new B(42));
+  A* a = new A;
+  A* c = new A;
+  a->b = x;
+  c->b = x;
+  cout << x.use_count() << endl;
+  delete a;
+  cout << x.use_count() << endl;
+  delete c;
+  cout << x.use_count() << endl;
+
+  return 0;
+}
+
diff --git a/c,cc/slicing.cc b/c,cc/slicing.cc
new file mode 100644
index 0000000..c89d99d
--- /dev/null
+++ b/c,cc/slicing.cc
@@ -0,0 +1,43 @@
+#include <iostream>
+#include <string>
+#include <vector>
+
+using namespace std;
+
+struct A {
+  public:
+    virtual string s() { return "a"; }
+};
+
+class B : public A {
+  public:
+    string s() { return "b"; }
+};
+
+B
+make_b()
+{
+  B b;
+  return b;
+}
+
+A
+make_a()
+{
+  return make_b();
+}
+
+int
+main(void)
+{
+  vector<A> x;
+  B b = make_b();
+  x.push_back(b);
+  cout << x[0].s() << endl;
+  B c;
+  x.push_back(c);
+  cout << x[1].s() << endl;
+
+  return 0;
+}
+
diff --git a/c,cc/struct_init.cc b/c,cc/struct_init.cc
new file mode 100644
index 0000000..e54724a
--- /dev/null
+++ b/c,cc/struct_init.cc
@@ -0,0 +1,33 @@
+#include <iostream>
+#include <utility>
+#include <vector>
+
+using namespace std;
+
+struct POD {
+  POD() { a = 2; }
+  POD(int x) { a = x; }
+  int a;
+};
+
+int
+main(void)
+{
+  vector<pair<char,char> > a;
+  pair<char,char> p = make_pair('a','b');
+  a.push_back(p);
+  vector<pair<char, char> > b(a);
+  cout << b[0].first << endl;
+  b[0].first = 'c';
+  cout << b[0].first << endl;
+
+  vector<POD> w;
+  POD x; x.a=3;
+  w.push_back(x);
+  POD y(x);
+  vector<POD> q(w);
+  cout << q[0].a << endl;
+
+  return 0;
+}
+
diff --git a/c,cc/vector_back.cc b/c,cc/vector_back.cc
new file mode 100644
index 0000000..cbc82f5
--- /dev/null
+++ b/c,cc/vector_back.cc
@@ -0,0 +1,24 @@
+#include <iostream>
+#include <vector>
+
+using namespace std;
+
+struct Foo {
+  int i;
+  char c;
+};
+
+int
+main(void)
+{
+  vector<Foo> foo;  
+  foo.push_back(Foo());
+  foo.back().i = 3;
+  foo.back().c = 'c';
+
+  for (vector<Foo>::iterator it = foo.begin(); it != foo.end(); it++)
+    cout << it->i << " " << it->c << endl;
+
+  return 0;
+}
+
diff --git a/c,cc/vector_pointer.cc b/c,cc/vector_pointer.cc
new file mode 100644
index 0000000..70251e6
--- /dev/null
+++ b/c,cc/vector_pointer.cc
@@ -0,0 +1,19 @@
+#include <vector>
+#include <iostream>
+
+using namespace std;
+
+int main(void)
+{
+  vector<char> x;
+  x.push_back('a');
+  x.push_back('b');
+  x.push_back('c');
+  char* p = &(x[1]);
+  cout << *p << endl;
+  x[1] = 'x';
+  cout << *p << endl;
+
+  return 0;
+}
+