C + +, the size of class

Does not allocate space for functions of classes and objects;

In a class where virtual functions are declared in virtual, a pointer is hidden that points to the virtual function table, which is the same for pure virtual functions;

For virtual inheritance, there is also a pointer to the parent class, which is a pointer to the virtual base class (Pointer to Virtual base class).

#include"stdafx.h"#include<iostream>using namespacestd; #include"T1.h"classtnull{};classti{inti;};classtic{inti; Charc;};classtf{voidFvoid){}};classt_vf{Virtual voidFvoid){}};classTif { Public:    void Set(intX) {i =x;}Private:    inti;};classTI_VF { Public:    Virtual void Set(intX) {i =x;}Private:    inti;};classti_v0f { Public:    Virtual void Set(intx) =0;Private:    inti;};classTI_SF {inti; Static voidsfvoid){}};classtt{TT () {}};classtxt{~TxT () {}};classttt{TTT () {}~TTT () {}Private: Tif*m_ptif;};classtttfff{ Public: Tttfff () {m_ptif=NewTif; M_ptif-Set(0); }    ~tttfff () {delete (m_ptif); M_ptif=0; }    voidF1 (void){}    voidF2 (void){}    voidF3 (void){}Private: Tif*m_ptif;};classttt_vfff{ Public: Ttt_vfff () {m_ptif=NewTif; M_ptif-Set(0); }    ~ttt_vfff () {delete (m_ptif); M_ptif=0; }    Virtual voidF1 (void){}    Virtual voidF2 (void){}    Virtual voidF3 (void){}Private: Tif*m_ptif;};voidT1 (void) {cout<<"sizeof (char) ="<<sizeof(Char) <<Endl; cout<<"sizeof (class tnull) ="<<sizeof(classTnull) <<Endl; cout<<"sizeof (class Ti) ="<<sizeof(classTi) <<Endl; cout<<"sizeof (class Tic) ="<<sizeof(classTic) <<Endl; cout<<"sizeof (class Tf) ="<<sizeof(classTF) <<Endl; cout<<"sizeof (class Tif) ="<<sizeof(classTIF) <<Endl; cout<<"sizeof (class T_VF) ="<<sizeof(classT_VF) <<Endl; cout<<"sizeof (class TI_VF) ="<<sizeof(classTI_VF) <<Endl; cout<<"sizeof (class ti_v0f) ="<<sizeof(classti_v0f) <<Endl; cout<<"sizeof (class ti_sf) ="<<sizeof(classTI_SF) <<Endl; cout<<"sizeof (class TT) ="<<sizeof(classTT) <<Endl; cout<<"sizeof (class TxT) ="<<sizeof(classTxT) <<Endl; cout<<"sizeof (class TTT) ="<<sizeof(classTTT) <<Endl; cout<<"sizeof (class tttfff) ="<<sizeof(classTTTFFF) <<Endl; cout<<"sizeof (class ttt_vfff) ="<<sizeof(classTTT_VFFF) <<Endl;    TTTFFF T; cout<<"sizeof (tttfff t) ="<<sizeof(t) <<endl;/*sizeof (tttfff t) = 4*/}/*sizeof (char) = 1sizeof (class tnull) = 1sizeof (class Ti) = 4sizeof (class Tic) = 8sizeof (class Tf) = 1sizeof (class Tif) = 4sizeof (class T_VF) = 4sizeof (class TI_VF) = 8sizeof (class ti_v0f) = 8sizeof (class ti_sf) = 4sizeof (class TT) = 1sizeof ( Class TxT) = 1sizeof (class TTT) = 4sizeof (class tttfff) = 4sizeof (class ttt_vfff) = 8sizeof (tttfff t) = 4 Press any key to continue ...*/

Extension: 1. C + + class size http://www.cnblogs.com/luxiaoxun/archive/2012/09/01/2666395.html

2. C + + virtual function table parsing http://blog.csdn.net/haoel/article/details/1948051

C + +, the size of class