C风格/ C ++的正确性，struct / union / enum标记与类型名称是否相同？

问题描述

下面的MyStruct（标记MyStruct）定义和MyStruct类型的类型定义似乎可以被gcc（至少4.6.2）和g ++完全编译。

The following definition of MyStruct (tag MyStruct) and type definition of type MyStruct seems perfectly compillable by gcc (at least 4.6.2) and by g++.

typedef struct MyStruct {
  int a;
  int b;
} MyStruct;

我的问题是：它是否容易出错（在C和/或C ++中）或样式不好使用标记名和类型名一样吗？

根据不是：

typedef struct tree_node tree_node;

但是我经常看到的代码风格如下：

But often I've seen code styled like:

1. typedef struct tagMyStruct {...} MyStruct;


2. typedef struct myStruct {。 ..} MyStruct;`


3. typedef struct _MyStruct {...} MyStruct; <是的，我知道下划线+大写字母

1. typedef struct tagMyStruct {...} MyStruct;
2. typedef struct myStruct {...} MyStruct;`
3. typedef struct _MyStruct {...} MyStruct; < yes, I know about underscore + capital letter

在每种情况下，有人都会在某种程度上使标签名称与不同名称。背后有任何实际的原因吗？

In each case someone went to some extent to make tag name differ from type name. Are there any practical reasons behind it?

侧面说明：我使用C ++编译器，但我希望这些定义与C兼容（我知道这对c ++来说是不好的风格）。为了维护某些调试工具的可用性，我需要所有标记名都有意义（例如，在未命名结构的情况下，不是自动生成的__unknown_something标记，例如，可以在Visual Studio类视图中查看）。

Side note: I use C++ compiler but I would like to be C compatible with those definitions (I know this is bad style for c++). For reasons of maintaining usability of some debug tools, I need all the tag names to be meaningful (not the automatically generated __unknown_something tags in case of unnamed structs you can, for example, see in visual studio class view).

同一个问题/问题也适用于联合和枚举。

Same issue/question apply to unions and enums.

推荐答案

从语言角度来讲，在C语言中完全可以和C ++，因为标记名存在于单独的命名空间（不是命名空间）中。

Language wise it is perfectly ok both in C and C++, as tag names exist in a separate name space (not namespace).

在C ++中，完全使用 typedef 绝对是不好的样式，因为它是多余的。无论您是否拥有 typedef MyStruct 和 struct MyStruct

In C++ it is definitely bad style to use the typedef at all, as it is redundant. You can use both MyStruct and struct MyStruct whether you have the typedef or not.

如果您认为C兼容性比C ++风格更为重要，那是您的选择。 ：-）

If you think C compatibility is more important than C++ style, that is your choice. :-)

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