1. Layout Cost for Adding Encapsulationinheritance don't have cost. But virtual function and virtual base class will add extra cost.
2. C++ Object ModelHow Compiler implement the OO:A Simple Object ModelA Table-driven Object ModelTwo conceptions: virtual table vtbl;vptr
How the Object Model Effects ProgramsX foobar(){ X xx; X *px = new X;
//foo() is virtual fucntion xx.foo(); px->foo(); delete px; return xx;};
3. A Keyword Distinctiontemplate <struct Type>template <class Type>struct mumble { ... };
4. An Object DistinctionC++ 直接支持三种programming paradigms (what's paradigm)1.procedural model2.abstract data type model String girl = "Anna" String daughter; daughter = girl; if (daughter == girl){ ... }
3.object-oriented model void check_in(Library_materials *pmat){ if (pmat->late()) pmat->check_in(); if (Lender *plend = pmat->reserved()) pmat->notify( plend ); }
PROBLEM:
Book book;thing1=book;//book is slicedthink.check_in();
Library_materials &thing2 = book;thing.check_in();
think1 = book 是ADT paradigm 的一种行为，用于OO就乱了Although the polymorphic manipulation of an object requires that the object be accessed either through apointer or a reference, the manipulation of a pointer or reference in C++ does not in itself necessarily resultin polymorphism!
The C++ language supports polymorphism in the following ways:1. Through a set of implicit conversions, such as the conversion of a derived class pointer to a pointer ofits public base type: shape *ps = new circle();2. Through the virtual function mechanism: ps->rotate();3. Through the dynamic_cast and typeid operators: if ( circle *pc = dynamic_cast< circle* >( ps )) ...
