Не могу создать производный класс от QComboBox

#ifndef __MTCOMBOBOX_H__
#define	__MTCOMBOBOX_H__

#include <QObject>
#include <QWidget>
#include <QComboBox>
#include <QStyledItemDelegate>

class MtComboBox : public QComboBox
{
    Q_OBJECT

public:
    MtComboBox(QWidget *parent=0);
    virtual ~MtComboBox();

private:

    QStyledItemDelegate* itemDelegate;

};

#endif	/* __MTCOMBOBOX_H__ */

#include "main.h"
#include "MtComboBox.h"

MtComboBox::MtComboBox(QWidget *parent) : QComboBox(parent)
{
 Q_UNUSED(parent);

 itemDelegate = new QStyledItemDelegate();
 this->setItemDelegate(itemDelegate);
}

MtComboBox::~MtComboBox()
{
 if(itemDelegate!=NULL)
  delete itemDelegate;
}

#include "libraries/MtComboBox.h"
...
MtComboBox *language;
...
language=new MtComboBox(this);

In file included from /usr/include/qt4/QtCore/qobjectdefs.h:45:0,
                 from /usr/include/qt4/QtCore/qobject.h:47,
                 from /usr/include/qt4/QtCore/QObject:1,
                 from src/libraries/MtComboBox.h:4:
/usr/include/qt4/QtCore/qnamespace.h:51:1: warning: return type defaults to ‘int’ [-Wreturn-type]
/usr/include/qt4/QtCore/qnamespace.h: In function ‘QT_MODULE’:
/usr/include/qt4/QtCore/qnamespace.h:54:1: error: unknown type name ‘namespace’
/usr/include/qt4/QtCore/qnamespace.h:58:4: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘{’ token
/usr/include/qt4/QtCore/qnamespace.h:1799:1: error: expected declaration specifiers before ‘Q_DECLARE_OPERATORS_FOR_FLAGS’
/usr/include/qt4/QtCore/qnamespace.h:1820:1: error: unknown type name ‘class’
/usr/include/qt4/QtCore/qnamespace.h:1820:21: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘QInternal’
/usr/include/qt4/QtCore/qnamespace.h:1875:2: error: expected declaration specifiers before ‘;’ token
In file included from /usr/include/qt4/QtCore/qobject.h:47:0,
                 from /usr/include/qt4/QtCore/QObject:1,
                 from src/libraries/MtComboBox.h:4:
/usr/include/qt4/QtCore/qobjectdefs.h:51:1: error: expected declaration specifiers before ‘QT_MODULE’
/usr/include/qt4/QtCore/qobjectdefs.h:55:1: error: unknown type name ‘class’
/usr/include/qt4/QtCore/qobjectdefs.h:143:1: error: expected declaration specifiers before ‘template’
/usr/include/qt4/QtCore/qobjectdefs.h:217:1: error: expected declaration specifiers before ‘Q_CORE_EXPORT’
/usr/include/qt4/QtCore/qobjectdefs.h:249:1: error: unknown type name ‘class’
/usr/include/qt4/QtCore/qobjectdefs.h:250:1: error: unknown type name ‘class’
/usr/include/qt4/QtCore/qobjectdefs.h:256:21: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘QGenericArgument’
/usr/include/qt4/QtCore/qobjectdefs.h:267:2: error: expected declaration specifiers before ‘;’ token
/usr/include/qt4/QtCore/qobjectdefs.h:269:1: error: unknown type name ‘class’
/usr/include/qt4/QtCore/qobjectdefs.h:269:21: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘QGenericReturnArgument’
/usr/include/qt4/QtCore/qobjectdefs.h:275:2: error: expected declaration specifiers before ‘;’ token
/usr/include/qt4/QtCore/qobjectdefs.h:277:1: error: expected declaration specifiers before ‘template’
/usr/include/qt4/QtCore/qobjectdefs.h:305:1: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘{’ token
In file included from /usr/include/qt4/QtCore/qobject.h:47:0,
                 from /usr/include/qt4/QtCore/QObject:1,
                 from src/libraries/MtComboBox.h:4:
/usr/include/qt4/QtCore/qobjectdefs.h:474:2: error: expected declaration specifiers before ‘;’ token
/usr/include/qt4/QtCore/qobjectdefs.h:476:26: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘&’ token
/usr/include/qt4/QtCore/qobjectdefs.h:483:5: error: unknown type name ‘QMetaObject’
/usr/include/qt4/QtCore/qobjectdefs.h:486:5: error: expected specifier-qualifier-list before ‘typedef’
/usr/include/qt4/QtCore/qobjectdefs.h:478:1: warning: empty declaration [enabled by default]
/usr/include/qt4/QtCore/qobjectdefs.h:491:31: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘:’ token
/usr/include/qt4/QtCore/qobjectdefs.h:494:1: error: unknown type name ‘QMetaObject’
/usr/include/qt4/QtCore/qobjectdefs.h:494:38: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘:’ token
In file included from /usr/include/qt4/QtCore/qstring.h:45:0,
                 from /usr/include/qt4/QtCore/qobject.h:48,
                 from /usr/include/qt4/QtCore/QObject:1,
                 from src/libraries/MtComboBox.h:4:
/usr/include/qt4/QtCore/qchar.h:51:1: error: expected declaration specifiers before ‘QT_MODULE’
/usr/include/qt4/QtCore/qchar.h:57:1: error: expected specifier-qualifier-list before ‘public’
/usr/include/qt4/QtCore/qchar.h:55:1: warning: empty declaration [enabled by default]
/usr/include/qt4/QtCore/qchar.h:72:1: error: unknown type name ‘class’
/usr/include/qt4/QtCore/qchar.h:72:21: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘QChar’
/usr/include/qt4/QtCore/qchar.h:367:1: error: expected declaration specifiers before ‘;’ token
/usr/include/qt4/QtCore/qchar.h:369:1: error: expected declaration specifiers before ‘Q_DECLARE_TYPEINFO’
/usr/include/qt4/QtCore/qchar.h:371:13: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘:’ token
/usr/include/qt4/QtCore/qchar.h:378:1: error: unknown type name ‘QChar’
/usr/include/qt4/QtCore/qchar.h:378:19: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘:’ token
/usr/include/qt4/QtCore/qchar.h:392:1: error: unknown type name ‘bool’
/usr/include/qt4/QtCore/qchar.h:392:21: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘==’ token
/usr/include/qt4/QtCore/qchar.h:393:1: error: unknown type name ‘bool’
/usr/include/qt4/QtCore/qchar.h:393:21: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘!=’ token
/usr/include/qt4/QtCore/qchar.h:394:1: error: unknown type name ‘bool’
/usr/include/qt4/QtCore/qchar.h:394:21: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘<=’ token
/usr/include/qt4/QtCore/qchar.h:395:1: error: unknown type name ‘bool’
/usr/include/qt4/QtCore/qchar.h:395:21: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘>=’ token
/usr/include/qt4/QtCore/qchar.h:396:1: error: unknown type name ‘bool’
/usr/include/qt4/QtCore/qchar.h:396:21: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘<’ token
/usr/include/qt4/QtCore/qchar.h:397:1: error: unknown type name ‘bool’
/usr/include/qt4/QtCore/qchar.h:397:21: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘>’ token
/usr/include/qt4/QtCore/qchar.h:400:1: error: unknown type name ‘Q_CORE_EXPORT’
/usr/include/qt4/QtCore/qchar.h:400:27: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘&’ token
In file included from /usr/include/qt4/QtCore/qatomic.h:46:0,
                 from /usr/include/qt4/QtCore/qbytearray.h:45,
                 from /usr/include/qt4/QtCore/qstring.h:46,
                 from /usr/include/qt4/QtCore/qobject.h:48,
                 from /usr/include/qt4/QtCore/QObject:1,
                 from src/libraries/MtComboBox.h:4:
/usr/include/qt4/QtCore/qbasicatomic.h:51:1: error: expected declaration specifiers before ‘QT_MODULE’
/usr/include/qt4/QtCore/qbasicatomic.h:128:2: error: expected declaration specifiers before ‘;’ token
/usr/include/qt4/QtCore/qbasicatomic.h:130:1: error: expected declaration specifiers before ‘template’
In file included from /usr/include/qt4/QtCore/qatomic_arch.h:66:0,
                 from /usr/include/qt4/QtCore/qbasicatomic.h:227,
                 from /usr/include/qt4/QtCore/qatomic.h:46,
                 from /usr/include/qt4/QtCore/qbytearray.h:45,
                 from /usr/include/qt4/QtCore/qstring.h:46,
                 from /usr/include/qt4/QtCore/qobject.h:48,
                 from /usr/include/qt4/QtCore/QObject:1,
                 from src/libraries/MtComboBox.h:4:
/usr/include/qt4/QtCore/qatomic_i386.h:51:1: error: unknown type name ‘bool’
/usr/include/qt4/QtCore/qatomic_i386.h:51:28: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘:’ token
/usr/include/qt4/QtCore/qatomic_i386.h:83:1: error: expected declaration specifiers before ‘template’
/usr/include/qt4/QtCore/qatomic_i386.h:112:1: error: unknown type name ‘bool’
/usr/include/qt4/QtCore/qatomic_i386.h:112:28: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘:’ token
/usr/include/qt4/QtCore/qatomic_i386.h:124:1: error: unknown type name ‘bool’
/usr/include/qt4/QtCore/qatomic_i386.h:124:28: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘:’ token
/usr/include/qt4/QtCore/qatomic_i386.h:136:1: error: unknown type name ‘bool’
/usr/include/qt4/QtCore/qatomic_i386.h:136:28: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘:’ token
/usr/include/qt4/QtCore/qatomic_i386.h:167:1: error: expected declaration specifiers before ‘template’
/usr/include/qt4/QtCore/qatomic_i386.h:180:1: error: expected declaration specifiers before ‘template’
/usr/include/qt4/QtCore/qatomic_i386.h:259:1: error: unknown type name ‘bool’
/usr/include/qt4/QtCore/qatomic_i386.h:259:28: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘:’ token
/usr/include/qt4/QtCore/qatomic_i386.h:264:1: error: unknown type name ‘bool’
/usr/include/qt4/QtCore/qatomic_i386.h:264:28: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘:’ token
/usr/include/qt4/QtCore/qatomic_i386.h:269:1: error: unknown type name ‘bool’
/usr/include/qt4/QtCore/qatomic_i386.h:269:28: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘:’ token
/usr/include/qt4/QtCore/qatomic_i386.h:304:1: error: expected declaration specifiers before ‘template’
/usr/include/qt4/QtCore/qatomic_i386.h:310:1: error: expected declaration specifiers before ‘template’
In file included from /usr/include/qt4/QtCore/qbytearray.h:45:0,
                 from /usr/include/qt4/QtCore/qstring.h:46,
                 from /usr/include/qt4/QtCore/qobject.h:48,
                 from /usr/include/qt4/QtCore/QObject:1,
                 from src/libraries/MtComboBox.h:4:
/usr/include/qt4/QtCore/qatomic.h:52:1: error: expected declaration specifiers before ‘QT_MODULE’
/usr/include/qt4/QtCore/qatomic.h:121:2: error: expected declaration specifiers before ‘;’ token
/usr/include/qt4/QtCore/qatomic.h:124:1: error: expected declaration specifiers before ‘template’
/usr/include/qt4/QtCore/qatomic.h:186:2: error: expected declaration specifiers before ‘;’ token
/usr/include/qt4/QtCore/qatomic.h:194:1: error: expected declaration specifiers before ‘template’
/usr/include/qt4/QtCore/qatomic.h:213:1: error: expected declaration specifiers before ‘template’
In file included from /usr/include/qt4/QtCore/qbytearray.h:48:0,
                 from /usr/include/qt4/QtCore/qstring.h:46,
                 from /usr/include/qt4/QtCore/qobject.h:48,
                 from /usr/include/qt4/QtCore/QObject:1,
                 from src/libraries/MtComboBox.h:4:
/usr/include/string.h:42:14: error: storage class specified for parameter ‘memcpy’
/usr/include/string.h:46:14: error: storage class specified for parameter ‘memmove’
/usr/include/string.h:147:12: error: storage class specified for parameter ‘strcoll’
/usr/include/string.h:150:15: error: storage class specified for parameter ‘strxfrm’
In file included from /usr/include/string.h:159:0,
                 from /usr/include/qt4/QtCore/qbytearray.h:48,
                 from /usr/include/qt4/QtCore/qstring.h:46,
                 from /usr/include/qt4/QtCore/qobject.h:48,
                 from /usr/include/qt4/QtCore/QObject:1,
                 from src/libraries/MtComboBox.h:4:
/usr/include/xlocale.h:39:4: error: storage class specified for parameter ‘__locale_t’
/usr/include/xlocale.h:42:20: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘locale_t’
In file included from /usr/include/qt4/QtCore/qbytearray.h:48:0,
                 from /usr/include/qt4/QtCore/qstring.h:46,
                 from /usr/include/qt4/QtCore/qobject.h:48,
                 from /usr/include/qt4/QtCore/QObject:1,
                 from src/libraries/MtComboBox.h:4:
/usr/include/string.h:162:59: error: expected declaration specifiers or ‘...’ before ‘__locale_t’
/usr/include/string.h:166:5: error: expected declaration specifiers or ‘...’ before ‘__locale_t’
/usr/include/string.h:172:14: error: storage class specified for parameter ‘strdup’
/usr/include/string.h:572:14: error: storage class specified for parameter ‘__stpncpy’
/usr/include/string.h:575:14: error: storage class specified for parameter ‘stpncpy’
In file included from /usr/include/qt4/QtCore/qbytearray.h:49:0,
                 from /usr/include/qt4/QtCore/qstring.h:46,
                 from /usr/include/qt4/QtCore/qobject.h:48,
                 from /usr/include/qt4/QtCore/QObject:1,
                 from src/libraries/MtComboBox.h:4:
/usr/lib/gcc/i486-linux-gnu/4.7/include/stdarg.h:40:27: error: storage class specified for parameter ‘__gnuc_va_list’
In file included from /usr/include/qt4/QtCore/qbytearray.h:49:0,
                 from /usr/include/qt4/QtCore/qstring.h:46,
                 from /usr/include/qt4/QtCore/qobject.h:48,
                 from /usr/include/qt4/QtCore/QObject:1,
                 from src/libraries/MtComboBox.h:4:
/usr/lib/gcc/i486-linux-gnu/4.7/include/stdarg.h:102:24: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘va_list’
In file included from /usr/include/qt4/QtCore/qstring.h:46:0,
                 from /usr/include/qt4/QtCore/qobject.h:48,
                 from /usr/include/qt4/QtCore/QObject:1,
                 from src/libraries/MtComboBox.h:4:
/usr/include/qt4/QtCore/qbytearray.h:71:1: error: expected declaration specifiers before ‘QT_MODULE’
/usr/include/qt4/QtCore/qbytearray.h:79:1: error: unknown type name ‘uint’
/usr/include/qt4/QtCore/qbytearray.h:80:1: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘{’ token
/usr/include/qt4/QtCore/qbytearray.h:82:1: error: unknown type name ‘uint’
/usr/include/qt4/QtCore/qbytearray.h:82:39: error: unknown type name ‘uint’
/usr/include/qt4/QtCore/qbytearray.h:92:1: error: expected declaration specifiers before ‘Q_CORE_EXPORT’
/usr/include/qt4/QtCore/qbytearray.h:93:1: error: expected declaration specifiers before ‘Q_CORE_EXPORT’
/usr/include/qt4/QtCore/qbytearray.h:98:51: warning: type defaults to ‘int’ in declaration of ‘QByteArray’ [-Wimplicit-int]
/usr/include/qt4/QtCore/qbytearray.h:98:62: error: expected ‘;’, ‘,’ or ‘)’ before ‘&’ token
/usr/include/qt4/QtCore/qbytearray.h:101:57: error: unknown type name ‘uint’
/usr/include/qt4/QtCore/qbytearray.h:106:1: error: expected declaration specifiers before ‘Q_CORE_EXPORT’
/usr/include/qt4/QtCore/qbytearray.h:107:1: error: expected declaration specifiers before ‘Q_CORE_EXPORT’
/usr/include/qt4/QtCore/qbytearray.h:128:1: error: unknown type name ‘Q_CORE_EXPORT’
/usr/include/qt4/QtCore/qbytearray.h:128:23: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘qChecksum’
/usr/include/qt4/QtCore/qbytearray.h:130:1: error: unknown type name ‘class’
/usr/include/qt4/QtCore/qbytearray.h:131:1: error: unknown type name ‘class’
/usr/include/qt4/QtCore/qbytearray.h:131:7: error: redefinition of parameter ‘QString’
In file included from /usr/include/qt4/QtCore/qobject.h:47:0,
                 from /usr/include/qt4/QtCore/QObject:1,
                 from src/libraries/MtComboBox.h:4:
/usr/include/qt4/QtCore/qobjectdefs.h:55:7: note: previous definition of ‘QString’ was here
In file included from /usr/include/qt4/QtCore/qstring.h:46:0,
                 from /usr/include/qt4/QtCore/qobject.h:48,
                 from /usr/include/qt4/QtCore/QObject:1,
                 from src/libraries/MtComboBox.h:4:
/usr/include/qt4/QtCore/qbytearray.h:132:1: error: unknown type name ‘class’
/usr/include/qt4/QtCore/qbytearray.h:133:1: error: expected declaration specifiers before ‘template’
/usr/include/qt4/QtCore/qbytearray.h:135:1: error: unknown type name ‘class’
/usr/include/qt4/QtCore/qbytearray.h:135:21: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘QByteArray’
/usr/include/qt4/QtCore/qbytearray.h:398:2: error: expected declaration specifiers before ‘;’ token
/usr/include/qt4/QtCore/qbytearray.h:400:18: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘:’ token
/usr/include/qt4/QtCore/qbytearray.h:590:19: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘&’ token
/usr/include/qt4/QtCore/qbytearray.h:597:1: error: unknown type name ‘Q_CORE_EXPORT’
/usr/include/qt4/QtCore/qbytearray.h:597:27: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘&’ token
/usr/include/qt4/QtCore/qbytearray.h:602:1: error: unknown type name ‘Q_CORE_EXPORT’
/usr/include/qt4/QtCore/qbytearray.h:602:26: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘qCompress’
/usr/include/qt4/QtCore/qbytearray.h:603:1: error: unknown type name ‘Q_CORE_EXPORT’
/usr/include/qt4/QtCore/qbytearray.h:603:26: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘qUncompress’
/usr/include/qt4/QtCore/qbytearray.h:604:1: error: unknown type name ‘QByteArray’
/usr/include/qt4/QtCore/qbytearray.h:604:35: warning: type defaults to ‘int’ in declaration of ‘QByteArray’ [-Wimplicit-int]
/usr/include/qt4/QtCore/qbytearray.h:604:45: error: expected ‘;’, ‘,’ or ‘)’ before ‘&’ token
/usr/include/qt4/QtCore/qbytearray.h:606:1: error: unknown type name ‘QByteArray’
/usr/include/qt4/QtCore/qbytearray.h:606:37: warning: type defaults to ‘int’ in declaration of ‘QByteArray’ [-Wimplicit-int]
/usr/include/qt4/QtCore/qbytearray.h:606:47: error: expected ‘;’, ‘,’ or ‘)’ before ‘&’ token
/usr/include/qt4/QtCore/qbytearray.h:610:1: error: expected declaration specifiers before ‘Q_DECLARE_TYPEINFO’
/usr/include/qt4/QtCore/qbytearray.h:611:1: error: expected declaration specifiers before ‘Q_DECLARE_SHARED’
In file included from /usr/include/qt4/QtCore/qobject.h:48:0,
                 from /usr/include/qt4/QtCore/QObject:1,
                 from src/libraries/MtComboBox.h:4:
/usr/include/qt4/QtCore/qstring.h:54:20: fatal error: string: Нет такого файла или каталога
compilation terminated.