Error: 'class name' redeclared as different kind of symbol?

I was facing the same error as asked in this question

I overcome with this error by solution of declaring class ahead of time in my .h file with the class parameter

I am having FFTBufferManager.h and FFTBufferManager.cpp f开发者_开发问答ile and using it in HomeView.h and HomeView.mm file

class FFTBufferManager,CAStreamBasicDescription,DCRejectionFilter;

But now I am having error as

#include "FFTBufferManager.h"
#include "aurio_helper.h"
#include "CAStreamBasicDescription.h"

class CAStreamBasicDescription,FFTBufferManager;  //here it shows this error
   EXpected Unqualified-id befor ',' token


@interface HomeView 
{
    FFTBufferManager*           fftBufferManager;
//it shows erros 
 EXpected Unqualified-id befor ',' token
    ISO c++ forbids declaration of FFTBufferManager with no type

}

    @property FFTBufferManager*     fftBufferManager;
 //shows error
'FFTBufferManager' is not a type

I'm gathering you're using both C++ and Objective-C.

I'd suggest renaming all your .cpp and .m files in which Objective-C and C++ code are meeting to use the extension .mm - this tells the compiler to use "Objective-C++" rules, and will stop a lot of compiler troubles.

Also, it seems CAStreamBasicDescritpion is a C++ class - you'll have to forward-declare it with class CAStreamBasicDescritpion;, not @class CAStreamBasicDescritpion; (note, no "at" sign) - the second form is only for forward-declaring Objective-C classes. This I suspect is the root cause of the particular error you have observed.

EDIT in response to comment: I'm not sure about your first new issue - that should work fine so long as both FFTBufferManager and CAStreamBasicDescription are C++ classes. As to your second one, depending on where exactly that line of code is (CAStreamBasicDescription thruFormat;) you may need to include the header rather than just the forward-declare: you're declaring an instance of CAStreamBasicDescription here, and the compiler needs to know its structure to do so.

You can't declare more than one class at a time.

Change your declarations to

class CAStreamBasicDescription;
class FFTBufferManager;

The compiler is looking for an unqualified-id because it believes that you're declaring a variable of type CAStreamBasicDescription, so it expects a variable name where you gave it a comma.

Looks like you are trying to create a class that already exists in one of the Cocoa frameworks.