classDate{public:Date(int year,int month,int day):_year(year),_month(month),_day(day){cout<<"Date(int year, int month, int day)"<<endl;}private:int _year;int _month;int _day;}; 2.2 std::initializer_list 那除了上面的场景呢,C++11还支持了STL里面的容器也可以这样去初始化 比如: ...
intmain(){//{} 必须与Date构造参数个匹配Date d1={20204,8,26};//{} 列表中可以有任意多个值vector<int>v1={2024,8,26,20,56};vector<int>v2({2024,8,26,20,56});std::initializer_list<int>mylist;mylist={10,20,30};cout<<sizeof(mylist)<<endl;cout<<mylist.begin()<<endl;cout<<...
最后,对 std::initializer_list 的访问只能通过 begin() 和 end() 进行循环遍历,遍历时取得的迭代器是只读的。因此,无法修改 std::initializer_list 中某一个元素的值,但是可以通过初始化列表的赋值对 std::initializer_list 做整体修改,代码如下: std::initializer_list<int> list; size_t n = list.size()...
#include<iostream>classClassX{public://直接是引用ClassX(intval1,intval2){std::cout<<"(int val1, int val2)版本构造函数被调用\n";std::cout<<val1<<"_"<<val2<<"\n\n";}ClassX(std::initializer_list<int>list){std::cout<<"(std::initializer_list<int> list)版本构造函数被调用\n";f...
#include <iostream>#include<sstream>#include<string>#include<initializer_list>structmyclass { std::strings; myclass(std::initializer_list<int>args) { std::stringstream ss;for(auto it = args.begin(); it != args.end(); ++it) {
In C++11, we got a handy way to initialize various containers. Rather than using push_back() or insert() several times, you can leverage a single constructor by taking an initializer list. For example, with a vector of strings, you can write: std::vector
使用std::initializer_list An object of type std::initializer_list is a lightweight proxy object that provides access to an array of objects of type const T. A std::initializer_list object is automatically constructed when: a braced-init-list is used to list-initialize an object, where the...
()};// 在 return 语句中复制列表初始化// 这不使用 std::initializer_list}};template<typenameT>voidtemplated_fn(T){}intmain(){S<int>s={1,2,3,4,5};// 复制初始化s.append({6,7,8});// 函数调用中的列表初始化std::cout<<"The vector size is now "<<s.c_arr().second<<" ints...
classA{public:A(std::initializer_list<int>param){// 构造函数}}; initializer_list介绍 它是一个模板类 它的实现很简单本质是就是一个指针和一个数组长度组成,源码如下: template<class_E>classinitializer_list{public:typedef_Evalue_type;typedefconst_E&reference;typedefconst_E&const_reference;typedefsize...
int array[5]; Copy If we want to initialize this array with values, we can do so directly via the initializer list syntax: #include <iostream> int main() { int array[] { 5, 4, 3, 2, 1 }; // initializer list for (auto i : array) std::cout << i << ' '; return 0; }...