方便的C ++结构初始化 [英] Convenient C++ struct initialisation

问题描述

我试图找到一种方便的方式来初始化'pod'C ++结构。现在，考虑以下结构：

  struct FooBar {
 int foo; 
 float bar; 
}; 
 //只是为了使所有示例在C和C ++中工作：
 typedef struct FooBar FooBar; 
  

如果我想在C（！）中方便地初始化它， >

  / * A * / FooBar fb = {.foo = 12，.bar = 3.4} //非法C ++，合法C 
  

注意，我想明确避免下面的符号，将来如果我在结构中更改任何，我就会打破我的脖子：

  / * B * / FooBar fb = {12,3.4}; //法律C ++，法律C，坏样式？ 
  

要在C ++中实现与在中相同（或至少类似） / * A * / 例如，我将实现一个愚蠢的构造函数：

  FooBar :: FooBar（int foo，float bar）：foo（foo），bar（bar）{} 
 //  - > 
 / * C * / FooBar fb（12，3.4）; 
  

这对沸水有好处，但不适合懒人（懒惰是好事， ？）。此外，它与 / * B * / 示例差不多，因为它没有明确说明哪个值到哪个成员。

所以，我的问题基本上是如何在C ++中实现类似 / * A * / 或更好的东西？
或者，我可以解释为什么我不应该这样做（即为什么我的心理范例是坏的）。

编辑 >。

解决方案

由于样式A 不要 style B 那么如何使用 style BX ：

  FooBar fb = {/*.foo=*/ 12，/*.bar=*/ 3.4}; // :) 
  

至少在某种程度上有帮助。

I'm trying to find a convenient way to initialise 'pod' C++ structs. Now, consider the following struct:

struct FooBar {
  int foo;
  float bar;
};
// just to make all examples work in C and C++:
typedef struct FooBar FooBar;

If I want to conveniently initialise this in C (!), I could simply write:

/* A */ FooBar fb = { .foo = 12, .bar = 3.4 }; // illegal C++, legal C

Note that I want to explicitly avoid the following notation, because it strikes me as being made to break my neck if I change anything in the struct in the future:

/* B */ FooBar fb = { 12, 3.4 }; // legal C++, legal C, bad style?

To achieve the same (or at least similar) in C++ as in the /* A */ example, I would have to implement an idiotic constructor:

FooBar::FooBar(int foo, float bar) : foo(foo), bar(bar) {}
// ->
/* C */ FooBar fb(12, 3.4);

Which is good for boiling water, but not suitable for lazy people (laziness is a good thing, right?). Also, it is pretty much as bad as the /* B */ example, as it does not explicitly state which value goes to which member.

So, my question is basically how I can achieve something similar to /* A */ or better in C++? Alternatively, I would be okay with an explanation why I should not want to do this (i.e. why my mental paradigm is bad).

EDIT

By convenient, I mean also maintainable and non-redundant.

解决方案

Since style A is not allowed in C++ and you don't want style B then how about using style BX:

FooBar fb = { /*.foo=*/ 12, /*.bar=*/ 3.4 };  // :)

At least help at some extent.

这篇关于方便的C ++结构初始化的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！