C++虚继承初始化顺序

3 月，跳不动了？>>>

1. 没有虚继承则从左往右

   	public D:public A,public B,public C{};
   	public D:public A,public C,public B{};
   

2. 有虚继承则先构造虚继承的类然后再从左往右(如果某个普通类中有虚表,也要先虚继承构造)

   毕竟要避免菱形集成,就怕普通集成中有同一个基类。先构建虚表。

   	#include<iostream>
   	class INT
   	{
   	public:
   		int a;
   		INT(int ca=1):a(ca){std::cout<<"cint"<<a<<std::endl;}
   		operator int(){return a;}
   		int operator =(int ca ){a = ca;return a;}
   	};
   
   	class Test
   	{
   	public:
   		Test(){std::cout<<"test"<<std::endl;}
   	};
   
   	class A
   	{
   	public:
   		INT a;
   		A(int aa=12):a(aa){a=aa;std::cout<<"ca"<<a<<std::endl;}
   	};
   	class B:public virtual A{
   	public:
   		B(int b=1):A(b){a=b;std::cout<<"cb"<<a<<std::endl;}
   	};
   	class C:public virtual A{
   	public:
   		C(int c=11):A(c){a=c;std::cout<<"cc"<<a<<std::endl;}
   		// int c;
   	};
   
   	class D:public virtual A{
   	public:
   		D(int dd=12):A(dd){std::cout<<"cd"<<std::endl;}
   	};
   
   	class E:public virtual A{
   	public:
   		E(int dd=12):A(dd){std::cout<<"cE"<<std::endl;}
   	};
   
   	class Z:public Test,public D,public C,public E{
   	};
   
   	int main()
   	{
   		Z z;
   		return 0;
   	}
   
   	/*
   	cint12
   	ca12
   	test
   	cd
   	cc11
   	cE
   	[Finished in 5.2s]
   	*/
   

来源：oschina

链接：https://my.oschina.net/u/3695598/blog/3211297