在c ++中通过类共享枚举 [英] Sharing enums in c++ over classes

问题描述

我的程序中有几个枚举，我想在不同的类中分享。

当我在每个类中定义它时，我得到一个重新定义错误。

然后我搜索Google，看到我应该把它放在另一个标题中。
我试图这样做，并将标题包含到每个类头中 - 我仍然有相同的错误。

在StackOverflow中搜索一些更多的内容说我应该把它们放在自己的命名空间里。
所以我试过：

  enum.h：
 
命名空间my_enums 
 {
枚举分类{DATA_STORAGE，DMS，E_COMMERCE，GAMING，RTES，SECURITY}; 
枚举技巧{CPP，JAVA，SCRIPT，WEB，SYSTEM，QA}; 
 enum company_policy {CHEAP，LAVISH，COST_EFFECTIVE}; 
} 
  

但这仍然不起作用：首先，如果告诉类包括标题：using namespace my_enums;我得到不明确的错误。

正确的方法是做什么？

提前感谢^ _ ^

解决方案

你还记得多重包围警卫吗？通常情况如下：

  #ifndef MY_HEADER_FILE_H 
 #define MY_HEADER_FILE_H 
 [... code ... ] 
 #endif 
  

并保护类型和枚举免于在编译单元中定义乘法。

I have a few enums in my program and I want to share it across different classes.

When I tried to define it in each class I got a "redefining" error.

Then I searched Google and saw that I should put it in a different header. I tried to to do that and included the header into every class header - I still got the same error.

Searched some more and found in StackOverflow a thread saying I should put them in their own namespace. So I tried:

enum.h:

namespace my_enums
{
enum classification {DATA_STORAGE,DMS,E_COMMERCE,GAMING,RTES,SECURITY};
enum skill { CPP, JAVA, SCRIPT, WEB, SYSTEM, QA };
enum company_policy {CHEAP, LAVISH, COST_EFFECTIVE};
}

But that still doesn't work: First, if tell classes that include the header to: "using namespace my_enums;" I get " is ambiguous" error.

What is the correct way to do what I'm trying to do?

Thanks in advance ^_^

解决方案

Did you remember the multiple inclusion guard? Normally looks like:

#ifndef MY_HEADER_FILE_H
#define MY_HEADER_FILE_H
[...code...]
#endif

and protects types and enums from getting defined multiply in a compilation unit.

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