在C++

Question

使用私有类时，没有在此范围内误差宣布我有一类

class myClass 
{ 
    private: 

     std::list <myInnerClass> mylists; 

     class myInnerClass 
     { 
      // Design for this private class 
     } 
} 

我不明白为什么行std::list <myInnerClass> mylists给了我以下错误：

- Type 'myInnerClass' was not declared in this scope 
    - Type 'myInnerClass' could not be resolved 

我错在哪里？

Answer 1

您在使用内部类声明它

之前修复：

class myInnerClass 
    { 
     // Design for this private class 
    }; 

    std::list <myInnerClass> mylists; 

Answer 2

您使用myInnerClass声明之前。

这段代码可以编译：

class myClass 
{ 
    private: 
     class myInnerClass 
     { 
      // Design for this private class 
     } 
     std::list <myInnerClass> mylists; 
} 

Answer 3

首先必须声明的内部类，然后你可以用它

您的代码

class myClass 
{ 
private: 
    std::list <myInnerClass> mylists; 
    class myInnerClass 
    { 
     // Design for this private class 
    } 
} 

正确的代码：

class myClass 
{ 
    private: 
    class myInnerClass 
     { 
      // Design for this private class 
     } 
      std::list <myInnerClass> mylists; 
    }