我收到错误消息：Missing; *之前，但我没有错过

Question

I have commented everything out and the code now looks like this.

//AOBSClass.h

#ifndef __AOBSCLASSHDR__
#define __AOBSCLASSHDR__

#include "IDriver.h"
#include "ActuationClass.h"

namespace AOBS
{
    class AOBSClass
    {
    public:
        AOBSClass(IDriver *driver);
        ~AOBSClass();

        IDriver *drivers;

        ActuationClass act;     

    private:

    };
}

#endif



// ActuationClass.h

#ifndef __ACTUATIONCLASSHDR__
#define __ACTUATIONCLASSHDR__

#include "AOBSClass.h"

namespace AOBS
{
    class ActuationClass
    {
    public:

        ActuationClass();
        ~ActuationClass();

        AOBSClass *aobs; // This line here

    private:

    };
}
#endif

I keep getting the errors below on the line shown above. I have no idea what could be causing it.

error C2143: syntax error : missing ';' before '*'
error C4430: missing type specifier - int assumed. Note: C++ does not support default-int

I'm using Visual Studio Express 2013.

Answer 1

The two files include each other! Just put

class AOBSClass;

in the beginning of ActuationClass.h.

Answer 2

You have a circular dependency. ActuationClass.h includes AOBClass.h and vice versa.

To resolve this, remove the #include "AOBClass.h" in ActuationClass.h and just forward declare the AOBSClass .

namespace AOBS
{
    class AOBSClass;      // Forward declare
    class ActuationClass
    {
    public:

        ActuationClass();
        ~ActuationClass();

        AOBSClass *aobs;

    private:

    };
}

Answer 3

You have circular includes. Both header files include each other. Generally, includes should go one way, like a tree structure.

A includes B includes C, etc

Also, as noted by others: a forward declaration can help with this sort of thing