不命名A在C ++中键入 [英] Does Not Name A Type in C++

问题描述

在C ++当我得到一个错误，说xxxxx不命名一个类型在yyy.h

这是什么意思？

yyy.h 包含 xxxx 的标头。

例如，我使用：

  typedef CP_M_ReferenceCounted FxRC; 
  

，我已将 CP_M_ReferenceCounted.h yyy.h

我缺少一些基本的理解，是什么？

解决方案

这似乎需要相应地引用命名空间。例如，下面的yyy.h和test.cpp与你的问题相同：

  // yyy.h 
 #ifndef YYY_H__ 
 #define YYY_H__ 
 
命名空间Yyy {
 
 class CP_M_ReferenceCounted 
 {
} 
 
} 
 
 #endif 
 
 //test.cpp 
 #includeyyy.h
 $ b b typedef CP_M_ReferenceCounted FxRC; 
 
 
 int main（int argc，char ** argv）
 {
 
 return 0; 
} 
  

错误是

  ...错误：CP_M_ReferenceCounted未命名类型
  

但添加一行using namespace Yyy;解决了以下问题：

  // test.cpp 
 #includeyyy.h
 // add this line 
 using namespace Yyy; 
 
 typedef CP_M_ReferenceCounted FxRC; 
 ... 
  

因此，请检查.h头文件中的命名空间范围。 p>

in C++ when i get an error that says xxxxx does not name a type in yyy.h

What does that mean?

yyy.h has included the header that xxxx is in.

Example, I use:

typedef CP_M_ReferenceCounted FxRC;

and I have included CP_M_ReferenceCounted.h in yyy.h

I am missing some basic understanding, what is it?

解决方案

That seems you need to referring the namespace accordingly. For example, following yyy.h and test.cpp have the same problem as yours:

//yyy.h
#ifndef YYY_H__
#define YYY_H__

namespace Yyy {

class CP_M_ReferenceCounted
{
};

}

#endif

//test.cpp
#include "yyy.h"

typedef CP_M_ReferenceCounted FxRC;


int main(int argc, char **argv)
{

        return 0;
}

The error would be

...error: CP_M_ReferenceCounted does not name a type

But add a line "using namespace Yyy;" fixs the problem as below:

//test.cpp
#include "yyy.h"
// add this line
using namespace Yyy;

typedef CP_M_ReferenceCounted FxRC;
...

So please check the namespace scope in your .h headers.

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