Why is QMutex unknown?

Question

I've included the QMutex header and using it as seen below. But I get the following error:

error C2146: syntax error : missing > ';' before identifier > '_RecorderParamsMutex'

error C4430: missing type specifier - int assumed. > Note: C++ does not support default-int

error C4430: missing type specifier -> int assumed. Note: C++ does not > support default-int

#ifndef RECORDERinterface_h
    #define RECORDERinterface_h
    #include "qstring.h"
    #include "ccc.h"
    #include "ddd.h"
    #include <qmutex.h>
    #include "eee.h"

using namespace Common; //for aaaaa

class RecorderInterface{
    //the implemented recorders are my friends, the may access all my private stuff :)
    friend class A;
    friend class B;

public:
    RecorderInterface();     
    bool            setParam(RecorderPrintParam *up);


private:
    QMutex          _RecorderParamsMutex;
};

#endif

Not to answer your question, but names like _RecorderParamsMutex (ones that begin with an underscore and an uppercase letter) are reserved for the C++ implementation - you are not allowed to create such names in your own code. — anon
ok thanks, have you a link to that standard? So I can take a further look at that naming standard. — Christoferw
The standard isn't available on line - you have to pay for it. There are various drafts knocking about though. — anon
i use the qmutex in other files the same way, and it works. its hard to test this in my current proejct, i can't strip out so much (the code above is still stripped for posting here) — Christoferw

Hans Passant Hans Passant · Accepted Answer · 2010-01-20T13:24:07

Looking at the header file, the class declarations are wrapped by an #ifdef. Try it like this:

#define QT_THREAD_SUPPORT
#include <qmutex.h>

This probably ought to be a project-level #define so other threading definitions are available as well.

Why is QMutex unknown?

3 Answers