nullptr was not declared in th
时间: 2023-04-30 14:01:48 浏览: 70
该错误提示是因为在代码中使用了nullptr关键字,但是该关键字在当前作用域中未被声明或定义。可能的原因是编译器版本过低或者编译器不支持C++11标准。解决方法是升级编译器或者使用其他替代方案,如使用NULL或0代替nullptr。
相关问题
[Error] 'nullptr' was not declared in this scope
As an AI language model, I don't have context of the code you are working on. However, I can provide you with a general explanation of the error message.
The error message "'nullptr' was not declared in this scope" is a compilation error that occurs when the compiler encounters an undefined symbol or variable. In C++, the 'nullptr' keyword is used to represent a null pointer. This error message is displayed when the compiler cannot find the 'nullptr' keyword in the current scope.
To fix this error, you need to include the appropriate header file, which defines the 'nullptr' keyword. In C++, the 'nullptr' keyword is defined in the 'cstddef' header file. So, you can add the following line at the beginning of your code:
```c++
#include <cstddef>
```
This will make sure that the 'nullptr' keyword is available in the current scope, and the error should be resolved.
Qt编译报错:error: 'nullptr' was not declared in this scope
这个报错是因为你的编译器版本不支持 C++11 标准中的 nullptr 关键字。解决方法有两种:
1. 升级编译器版本到支持 C++11 标准的版本,例如 gcc 4.6 或以上版本。
2. 在代码中使用 NULL 宏替换 nullptr,NULL 宏在旧的 C++ 标准中已经定义。或者手动定义 nullptr 宏:
```
#if __cplusplus < 201103L
#define nullptr NULL
#endif
```
建议使用第一种方法,升级编译器版本,因为 C++11 标准中还有很多其他新特性也非常有用。