Adding items to a list

Monkey666

I can't work out actually how to use your operator QString() const.

loladiro

The posts must have crossed in the air ;). The QString() const method is an "explicit coversion operator":http://msdn.microsoft.com/en-us/library/ts48df3y(v=vs.80).aspx . However, be aware that there are also many bugs that may follow from the misuse of this laguage feature.

EDIT: you can use it just like ou would in C# (i.e. without doing anything special)

Monkey666

That's what I thought but get compiler error:

error: no matching function for call to 'QListWidget::addItem(const ProcInfo&)'

Monkey666

Actually there are more compile errors I should have mentioned which are most likely causing this:

error: no match for 'operator=' in 'p = procList.std::list<_Tp, _Alloc>::begin with _Tp = int, _Alloc = std::allocator<int>'

loladiro

Sorry but I can't reproduce. This all works:
@
class ProcInfo
{
public:
int id;
ProcInfo() : id(1234)
{}
operator QString() const
{
return QString::number(id);
}
};

void print(QString print)
{
qDebug() << print;
}

int main(int argc, char *argv[])
{
QApplication a(argc, argv);

QList< ProcInfo > list1;
list1 << ProcInfo();
QList< ProcInfo >::const_iterator i = list1.begin();

std::list< ProcInfo > list2;
list2.push_back(ProcInfo());

std::list< ProcInfo >::const_iterator i2 = list2.begin();

print(*i2);

print (*(i));

QListWidget widget;
widget.addItem(*i);

std::list< ProcInfo >::const_iterator p = list2.begin();

for (p=list2.begin();p!=list2.end(); ++p)
{
    widget.addItem(*p);
}

widget.show();

const ProcInfo p2;
print(p2);

return a.exec(&#41;;

}
@

Monkey666

Ok I've managed to get rid of all compile errors except this one:

error: expected type-specifier before 'QString'

And the error points to the operator:

@
class ProcInfo
{
public:
HANDLE Proc;
DWORD Base;
int ID;
operator QString() const
{
return QString::number(ID);
}
};@

loladiro

did you #include <QString>?

Monkey666

That fixed that but now I have another problem /sigh.

I have declared std::list<ProcInfo> procList; inside a header file, and that header file is included in the main cpp file which I am doing this all in, however I get error:

error: multiple definition of `procList'

There is definitely only 1 definition and it's inside the h file so I'm a little confused, maybe c++ isn't for me :(

loladiro

There's not much we can do without seeing the header file ...

Monkey666

proc.h

@
#include <windows.h>
#include <list>
#include <QString>

#ifndef PROC_H
#define PROC_H

#endif // PROC_H

class ProcInfo
{
public:
HANDLE Proc;
DWORD Base;
int ID;
operator QString() const
{
return QString::number(ID);
}
};

std::list< ProcInfo > procList;

bool createProcessList();
DWORD GetModuleBase(LPSTR lpModuleName, DWORD dwProcessId);
@

proc.cpp

@
#include <windows.h>
#include <iostream>
#include <string>
#include <tlhelp32.h>
#include "proc.h"
#include "misc.h"

using namespace std;

bool createProcessList()
{
PROCESSENTRY32 entry;
entry.dwSize = sizeof(PROCESSENTRY32);

HANDLE snapshot = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, NULL);

if (Process32First(snapshot, &entry;) == TRUE)
{
    while (Process32Next(snapshot, &entry;) == TRUE)
    {
        char *procName;
        strcpy_wc(procName, entry.szExeFile);
        if (stricmp(procName, "pol") == 0)
        {
            ProcInfo *p = new ProcInfo();
            p->Proc = OpenProcess(PROCESS_ALL_ACCESS,FALSE,entry.th32ProcessID);
            p->ID = entry.th32ProcessID;
            p->Base = GetModuleBase("test.dll", entry.th32ProcessID);
            procList.push_back(*p);
        }
    }
    if (procList.empty())
       return false;
    return true;
}

CloseHandle(snapshot);
return 0;

}

DWORD GetModuleBase(LPSTR lpModuleName, DWORD dwProcessId)
{
MODULEENTRY32 lpModuleEntry = {0};
HANDLE hSnapShot = CreateToolhelp32Snapshot( TH32CS_SNAPMODULE, dwProcessId );
if(!hSnapShot)
return NULL;
lpModuleEntry.dwSize = sizeof(lpModuleEntry);
BOOL bModule = Module32First( hSnapShot, &lpModuleEntry; );
while(bModule)
{
char *foundModule;
strcpy_wc(foundModule, lpModuleEntry.szModule);
if(!strcmp( foundModule, lpModuleName ) )
{
CloseHandle( hSnapShot );
return (DWORD)lpModuleEntry.modBaseAddr;
}
bModule = Module32Next( hSnapShot, &lpModuleEntry; );
}
CloseHandle( hSnapShot );
return NULL;
}
@

That error points to line 11 in proc.cpp.

loladiro

Well, my first comment is: fix your "include guards":http://en.wikipedia.org/wiki/Include_guard

Monkey666

I'll be honest, I don't really get it :/

loladiro

Yes! Let me explain. In C (and C++) an #include directive will include the file regardless of whether it has been included before. You can litterally compare this to copy'n'past-ing the header file into the source code whenever there is an #include directive. The include guards are used to make sure every header file is only included once. E.g. if your header file would usually be
@
class Dummy
{};
@
you'd have to use
@
#ifndef DUMMY_H //i.e. if dummy.h has never been included before
#define DUMMY_H //remember that it has been included

class Dummy
{};

#endif //endif after all statements
@
In your case the include guards have to enclose all of your statements (the header files not necessarily because they have their own include guards, but it's usually best to have the include guards be the first and last satements in your header files)

Monkey666

Ok so if I understand you it should be:

@
#include <windows.h>
#include <list>
#include <QString>

#ifndef PROC_H
#define PROC_H

class ProcInfo
{
public:
HANDLE Proc;
DWORD Base;
int ID;
operator QString() const
{
return QString::number(ID);
}
};

std::list<ProcInfo> procList;

bool createProcessList();
DWORD GetModuleBase(LPSTR lpModuleName, DWORD dwProcessId);

#endif // PROC_H@

But I still get the same error.

loladiro

In the compiler output window there should be information about where the compiler thinks that procList has been declared (something like "previously declared here: " )

Monkey666

c:\QtSDK\Desktop\Qt\4.7.3\mingw\include\QtCore\qatomic_i386.h:125: error: first defined here

loladiro

Hmm... try to use
@ inline operator QString() const
{
return QString::number(ID);
}
@

Monkey666

Same error :( The error is on procList anyways not ProcInfo, it doesn't make alot of sense to me :/

cincirin

If you wish procList in header, you need to declare it in cpp file, and define in header as
@extern std::list< ProcInfo > procList@

dangelog

Guys. It's not a "try and guess" process. He defined a global variable inside a header. As soon as that header gets included in two or more translation units, the compiler will output multiple definitions of the same name. And the linker will complain. Put that definition in ONE translation unit and you'll be ok.