如何将多个值分配到一个struct一次？ [英] how to assign multiple values into a struct at once?

问题描述

我可以为一个结构美孚做这个初始化：

 富富= {一堆的，物联网，初始化};
 

不过，我不能做到这一点：

 富富;
富= {一堆的，物联网，初始化};
 

于是，两个问题：

1. 为什么我不能做后者，仅用于初始化前一个特殊的构造？



2. 我该怎么办类似第二个例子东西，即在code的单行声明一堆的结构变量它已经被初始化后？我试图避免诸多变数做到这一点对于大型结构：

    富富;foo.a = 1;
   foo.b = 2;
   foo.c的= 3;
   // ...循环往复
    

解决方案

首先是一个聚合初始化 - 你可以在那些读了，并在该解决方案已被标签初始化：

<一个href=\"http://stackoverflow.com/questions/3016107/what-is-tagged-structure-initialization-syntax\">What被标记结构初始化语法？

这是一个特殊的初始化语法，你不能做你的结构初始化后类似的东西。你可以做的是提供一个成员（或非成员）函数把你的一系列的值作为参数，你再成员函数内分配 - 这将让你做到这一点的方式，同样的结构初始化后简洁（你写后的功能当然是第一次！）

I can do this on initialization for a struct Foo:

Foo foo =  {bunch, of, things, initialized};

but, I can't do this:

Foo foo;
foo = {bunch, of, things, initialized};

So, two questions:

1. Why can't I do the latter, is the former a special constructor for initialization only?

2. How can I do something similar to the second example, i.e. declare a bunch of variables for a struct in a single line of code after it's already been initialized? I'm trying to avoid having to do this for large structs with many variables:

   Foo foo;
   
   foo.a = 1;
   foo.b = 2;
   foo.c = 3;
   //... ad infinitum
   

解决方案

The first is an aggregate initializer - you can read up on those and tagged initializers at this solution:

What is tagged structure initialization syntax?

It is a special initialization syntax, and you can't do something similar after initialization of your struct. What you can do is provide a member (or non-member) function to take your series of values as parameters which you then assign within the member function - that would allow you to accomplish this after the structure is initialized in a way that is equally concise (after you've written the function the first time of course!)

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