#pragma once in main file
时间: 2024-05-25 09:11:58 浏览: 12
`#pragma once` is a preprocessor directive that ensures a header file is only included once in a compilation unit. It is typically added to the beginning of a header file to prevent multiple inclusions of the same file, which can cause errors due to redefinitions of symbols or multiple definitions of the same data. Adding `#pragma once` to the main file has no effect, as it is not a header file that is meant to be included by other files.
相关问题
cpp #pragma once in main file
在主文件中使用#pragma once来避免重定义问题是一种常见且有效的方法。 #pragma once是一种编译器指令,它可以确保头文件只被编译一次,无论它被包含多少次。这种写法省去了重复打开文件的操作,提高了编译效率。因此,推荐在主文件中使用#pragma once来避免重定义问题。 [2<span class="em">1</span><span class="em">2</span><span class="em">3</span>
#### 引用[.reference_title]
- *1* *2* *3* [#ifndef 和#pragma once](https://blog.csdn.net/Alatebloomer/article/details/80222316)[target="_blank" data-report-click={"spm":"1018.2226.3001.9630","extra":{"utm_source":"vip_chatgpt_common_search_pc_result","utm_medium":"distribute.pc_search_result.none-task-cask-2~all~insert_cask~default-1-null.142^v92^chatsearchT3_1"}}] [.reference_item style="max-width: 100%"]
[ .reference_list ]
(warning)#pragma once in main file
`#pragma once` is a preprocessor directive that ensures the header file is included only once during compilation. It's a non-standard method but widely supported by compilers.
The warning you're seeing suggests that `#pragma once` is being used in a source file (main file) instead of a header file. This can cause issues if the source file is included multiple times in different parts of the program.
To fix this warning, you should remove `#pragma once` from the source file and only use it in header files.
相关推荐
![rar](https://img-home.csdnimg.cn/images/20210720083606.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)