在结构类型后定义结构变量 [英] Defining structure variable after structure type

问题描述

#include <iostream>

struct people 
{
    int id;
} person; // that part

int main()
{
    person = {3};   
    std::cout << person.id;

    return 0;
}

我想问您有关初始化结构的问题（嗯，不是初始化。正在创建结构类型...我真的不知道你怎么称呼这个）。我看到了一些结构后面的关键字，例如这里的人。全部没有任何typedef。

I want to ask you about initializing a structure (well, not initialization...creating structure type...I don't really know how do you call this). Once I've seen some keyword after structure, like the "person" here. All without any typedef.

我做了一点研究，发现它用于直接在结构之后定义变量。

I did a little research and found out that it's used to define a variable directly after the structure.

但是，我上面发布的代码无法编译-它表示语法错误，缺少分号和类似的废话，表示该表达式无效。

However, my code I posted above doesn't compile - it says syntax error, missing semicolon and crap like that meaning the expression is not valid.

这是做什么用的，以及如何使用它？

What is this used for, and how to use this?

推荐答案

您不能在常规分配中使用结构初始化语法，它必须是在声明变量时完成：

You can't use the structure initialization syntax in a normal assignment, it has to be done when you declare your variable:

struct people 
{
    int id;
} person = { 3 };

如果您具有C ++ 11兼容的编译器，则可以使用统一初始化语法，稍后可以复制：

If you have a C++11 compatible compiler, you can use the uniform initialization syntax to copy later though:

person = people { 3 };

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