1.5.1.1 Basic knowledge

• For all container, Copy in, Copy out. In C++11, you can use emplace_back to build object directly on the vector to avoid copy.
  int j = 10; 
  vector<int> vc; 
  vc.push_back(j); // not j, but copy of j to vc 
   
  int i = vc.pop_back(); // 
  i = -99 // when you modify i, not effect on vc
• Even copy in, copy out. vector is better than array in C language, see demo code below:
  Foo farray[50]; //default ctor has been called 50 times. 
  Foo *parray = new Foo[50]; Same, ctor will be called 50 times. 
   
  vector<Foo> fvc; // no default ctor has been called. 
  fvc.reserve(50);
• Anytime you want to write new [..] just for allocate dynamic array, using a vector or string instead, and using reserve() to allocate enough space.
• Copy in and copy out can cause efficient problem. Furthermore, It brings another problem. when you inserting a derived class object into a container of base class objects is always error(slicing error). In order to fight this problem, you can use container of pointer. But it will cause resource leaking problem if you forget or an exception is thrown. So a better choice is use smart pointer. But don’t use auto_ptr in any container, It’s prohibited in c++, and produce a compiler error, see effective stl item 8.
• All container is not thread-safe. It’s your duty to make thread-safe, and thread-safe is OS depended. Detail can be seen effective STL item 12
  getMutexFor(v); 
  // do something on v. 
  releaseMutexFor(v);
• There are three kinds of for-loop container syntax;
  for(auto it = con.begin(), itend != con.end() 
           it !=itend ; ++it){ 
     foo(*it); 
  } 
   
  for_each(con.begin(), con.end(), [](Element& e){ 
     foo(e); 
  }); 
   
  for(auto & e : con){ 
     foo(e); 
  }