Copy Constructor的构造操作 有三种情况,会以一个object的内容作为另一个class object的初值: 1. 对一个object做显式的初始化操作 class X{…}; X a; X b = a; 2.当object被当做参数交给某个函数: X a; void foo(X x); foo(a); 3. 当返回值为object: X foo { X a; return a; } 假设class X显式定义了一个copy constructor,类似下面这样: X::X(
Reference: TutorialPoints, GeekforGeeks The copy constructor is a constructor which creates an object by initializing it with an object of the same class, which has been created previously. The copy constructor is used to: Initialize one object from
今天新写了一个类.然后对这个类使用STL中的vector,碰到错误: no copy constructor available or copy constructor is declared 'explicit' 假设碰到同样错误.能够检查一下重载的拷贝构造函数以及重载的'='运算符函数是否有问题,注意输入的參数必须是const类型的,少了constkeyword不行.
题目: In which of the following scenarios is a Copy Constructor called or invoked? A. When no conversion function exists for converting the class object to another class object B. When an existing object is assigned an object of its own class C.
前言 在三种情况下,会以一个 object 的内容作为另一个 class object 的初值: object明确初始化 class X{...}; X x; X xx = x; object 被当作参数交与某个函数 extern void foo(X x); void bar(){ X xx; foo(xx);//作为第一个参数的初值(不明显的初始化) } 函数返回值是一个 class object X foo_bar(){ X xx; ... return xx; } 如果开发者已经明确定义
C++ Code 123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354 #include <stdio.h> #include <stdlib.h> #include <string.h> #include <iostream> using namespace std; class Base { publi