Code improvements based on c++11 standard (ranged for loops and nullptr).

Signed-off-by: Michele Calgaro <michele.calgaro@yahoo.it>

21 files changed, 120 insertions, 132 deletions

diff --git a/agent/listeneradapter.cpp b/agent/listeneradapter.cpp
index ad4730ed5..39e7e8d36 100644
--- a/agent/listeneradapter.cpp
+++ b/agent/listeneradapter.cpp
@@ -34,7 +34,7 @@ namespace Agent
 // ListenerAdapter
 //--------------------------------------
 
-ListenerAdapter *ListenerAdapter::m_theListenerAdapter = NULL;
+ListenerAdapter *ListenerAdapter::m_theListenerAdapter = nullptr;
 
 ListenerAdapter *ListenerAdapter::instance()
 {
@@ -51,17 +51,15 @@ ListenerAdapter::ListenerAdapter(TQObject *parent) : TQObject(parent)
 
 Listener* ListenerAdapter::findListener(PolkitAgentListener *listener)
 {
-  TQValueList<Listener*>::iterator listerIt;
-  for (listerIt = m_listeners.begin(); listerIt != m_listeners.end(); ++listerIt)
+  for (Listener *&listItem : m_listeners)
   {
-    Listener *listItem = *listerIt;
     if (listItem && listItem->listener() == listener)
     {
       return listItem;
     }
   }
 
-  return NULL;
+  return nullptr;
 }
 
 void ListenerAdapter::polkit_tqt_listener_initiate_authentication(PolkitAgentListener *listener,
@@ -74,7 +72,7 @@ void ListenerAdapter::polkit_tqt_listener_initiate_authentication(PolkitAgentLis
   Identity::List idents;
   Details dets(details);
   GList *identity;
-  for (identity = g_list_first(identities); identity != NULL; identity = g_list_next(identity))
+  for (identity = g_list_first(identities); identity != nullptr; identity = g_list_next(identity))
   {
     idents.append(Identity((PolkitIdentity*)identity->data));
   }
diff --git a/agent/listeneradapter.h b/agent/listeneradapter.h
index b05d9966f..18d36d60b 100644
--- a/agent/listeneradapter.h
+++ b/agent/listeneradapter.h
@@ -73,7 +73,7 @@ class ListenerAdapter : public TQObject
     void removeListener(Listener *listener);
     Listener* findListener(PolkitAgentListener *listener);
 
-    explicit ListenerAdapter(TQObject *parent = 0);
+    explicit ListenerAdapter(TQObject *parent = nullptr);
     TQValueList<Listener*> m_listeners;
 
     // Disable copy
diff --git a/agent/polkit-tqt-agent-listener.cpp b/agent/polkit-tqt-agent-listener.cpp
index 2ff78eaf6..8e41c7c3b 100644
--- a/agent/polkit-tqt-agent-listener.cpp
+++ b/agent/polkit-tqt-agent-listener.cpp
@@ -64,7 +64,7 @@ Listener::~Listener()
   {
     polkit_agent_listener_unregister(d->registeredHandle);
   }
-  if (d->listener != NULL)
+  if (d->listener != nullptr)
   {
     g_object_unref(d->listener);
   }
@@ -72,19 +72,19 @@ Listener::~Listener()
 
 bool Listener::registerListener(const PolkitTQt::Subject &subject, const TQString &objectPath)
 {
-  GError *error = NULL;
+  GError *error = nullptr;
 
   d->registeredHandle = polkit_agent_listener_register(d->listener,
-          POLKIT_AGENT_REGISTER_FLAGS_NONE, subject.subject(), objectPath.ascii(), NULL, &error);
+          POLKIT_AGENT_REGISTER_FLAGS_NONE, subject.subject(), objectPath.ascii(), nullptr, &error);
 
-  if (error != NULL)
+  if (error != nullptr)
   {
     tqWarning(TQString("Cannot register authentication agent: %1").arg(error->message));
     g_error_free(error);
     return false;
   }
 
-  if (d->registeredHandle == NULL)
+  if (d->registeredHandle == nullptr)
   {
     tqWarning(TQString("Cannot register authentication agent!"));
     return false;
diff --git a/agent/polkit-tqt-agent-listener.h b/agent/polkit-tqt-agent-listener.h
index 30115dd8e..639382761 100644
--- a/agent/polkit-tqt-agent-listener.h
+++ b/agent/polkit-tqt-agent-listener.h
@@ -63,7 +63,7 @@ class POLKIT_TQT_EXPORT Listener : public TQObject
     /**
      * \brief Constructor of Listener class
      */
-    Listener(TQObject *parent = 0);
+    Listener(TQObject *parent = nullptr);
 
     /**
      * \brief Constructor of Listener class from PolkitAgentListener
@@ -73,7 +73,7 @@ class POLKIT_TQT_EXPORT Listener : public TQObject
      * \param listener Pointer to the PolkitAgentListener
      * \param parent
      */
-    explicit Listener(PolkitAgentListener *listener, TQObject *parent = 0);
+    explicit Listener(PolkitAgentListener *listener, TQObject *parent = nullptr);
 
     virtual ~Listener();
 
diff --git a/agent/polkit-tqt-agent-session.cpp b/agent/polkit-tqt-agent-session.cpp
index eb8460be4..3d0da6153 100644
--- a/agent/polkit-tqt-agent-session.cpp
+++ b/agent/polkit-tqt-agent-session.cpp
@@ -66,7 +66,7 @@ void Session::Private::completed(PolkitAgentSession *s, gboolean gained_authoriz
   {
     g_object_unref(session->d->polkitAgentSession);
   }
-  session->d->polkitAgentSession = 0;
+  session->d->polkitAgentSession = nullptr;
 }
 
 void Session::Private::request(PolkitAgentSession *s, gchar *request, gboolean echo_on,
@@ -168,7 +168,7 @@ AsyncResult::~AsyncResult()
 
 void AsyncResult::setCompleted()
 {
-  if (d->result == NULL)
+  if (d->result == nullptr)
   {
     return;
   }
@@ -178,12 +178,12 @@ void AsyncResult::setCompleted()
   {
     g_object_unref(d->result);
   }
-  d->result = NULL;
+  d->result = nullptr;
 }
 
 void AsyncResult::setError(const TQString &text)
 {
-  if (d->result == NULL)
+  if (d->result == nullptr)
   {
     return;
   }
diff --git a/agent/polkit-tqt-agent-session.h b/agent/polkit-tqt-agent-session.h
index 9f3e813d8..a122654a2 100644
--- a/agent/polkit-tqt-agent-session.h
+++ b/agent/polkit-tqt-agent-session.h
@@ -95,8 +95,8 @@ class POLKIT_TQT_EXPORT Session : public TQObject
      * \param result Result of the authentication action. Must be finished using complete() method.
      * \param parent
      */
-    Session(const Identity &identity, const TQString &cookie, AsyncResult *result = 0,
-            TQObject *parent = 0);
+    Session(const Identity &identity, const TQString &cookie, AsyncResult *result = nullptr,
+            TQObject *parent = nullptr);
 
     /**
      * Create a new authentication session from PolkitAgentSession object
@@ -106,7 +106,7 @@ class POLKIT_TQT_EXPORT Session : public TQObject
      * \param pkAgentSession PolkitAgentSession object
      * \param parent
      */
-    explicit Session(PolkitAgentSession *pkAgentSession, TQObject *parent = 0);
+    explicit Session(PolkitAgentSession *pkAgentSession, TQObject *parent = nullptr);
 
     /**
      * Destroy authentication session.
@@ -136,7 +136,7 @@ class POLKIT_TQT_EXPORT Session : public TQObject
     /**
      * Get AsyncResult that can be used to finish authentication operation
      *
-     * \return AsyncResult object or NULL if it is not set
+     * \return AsyncResult object or nullptr if it is not set
      */
     AsyncResult *result();
 
diff --git a/agent/polkit-tqt-listener.cpp b/agent/polkit-tqt-listener.cpp
index 269dcf7ec..9275e0783 100644
--- a/agent/polkit-tqt-listener.cpp
+++ b/agent/polkit-tqt-listener.cpp
@@ -53,7 +53,7 @@ static void polkit_tqt_listener_init(PolkitTQtListener *listener)
 static void polkit_tqt_listener_finalize(GObject *object)
 {
   PolkitTQtListener *listener = POLKIT_TQT_LISTENER(object);
-  if (G_OBJECT_CLASS(polkit_tqt_listener_parent_class)->finalize != NULL)
+  if (G_OBJECT_CLASS(polkit_tqt_listener_parent_class)->finalize != nullptr)
   {
     G_OBJECT_CLASS(polkit_tqt_listener_parent_class)->finalize(object);
   }
@@ -72,7 +72,7 @@ static void polkit_tqt_listener_class_init(PolkitTQtListenerClass *klass)
 
 PolkitAgentListener *polkit_tqt_listener_new(void)
 {
-  return POLKIT_AGENT_LISTENER(g_object_new(POLKIT_TQT_TYPE_LISTENER, NULL));
+  return POLKIT_AGENT_LISTENER(g_object_new(POLKIT_TQT_TYPE_LISTENER, nullptr));
 }
 
 static void cancelled_cb(GCancellable *cancellable, gpointer user_data)
@@ -95,7 +95,7 @@ static void polkit_tqt_listener_initiate_authentication(PolkitAgentListener *age
 
   ListenerAdapter::instance()->polkit_tqt_listener_initiate_authentication(agent_listener,
           action_id, message, icon_name, details, cookie, identities, cancellable, result);
-  if (cancellable != NULL)
+  if (cancellable != nullptr)
   {
     g_signal_connect(cancellable, "cancelled", G_CALLBACK(cancelled_cb), agent_listener);
   }
diff --git a/core/polkit-tqt-authority.cpp b/core/polkit-tqt-authority.cpp
index d8e4aa297..abe776245 100644
--- a/core/polkit-tqt-authority.cpp
+++ b/core/polkit-tqt-authority.cpp
@@ -33,7 +33,7 @@ namespace PolkitTQt
 // General functions
 //--------------------------------------
 
-Authority *Authority::m_theAuthority = NULL;
+Authority *Authority::m_theAuthority = nullptr;
 
 Authority* Authority::instance(PolkitAuthority *authority)
 {
@@ -83,7 +83,7 @@ ActionDescription::List actionsToListAndFree(GList *glist)
 class Authority::Private
 {
   public:
-    Private(Authority *qq) : q(qq), pkAuthority(NULL), m_hasError(false)
+    Private(Authority *qq) : q(qq), pkAuthority(nullptr), m_hasError(false)
     {
     }
 
@@ -169,11 +169,11 @@ void Authority::Private::init()
   m_revokeTemporaryAuthorizationsCancellable = g_cancellable_new();
   m_revokeTemporaryAuthorizationCancellable = g_cancellable_new();
 
-  GError *gerror = NULL;
-  if (pkAuthority == NULL)
+  GError *gerror = nullptr;
+  if (pkAuthority == nullptr)
   {
-    pkAuthority = polkit_authority_get_sync(NULL, &gerror);
-    if (gerror != NULL)
+    pkAuthority = polkit_authority_get_sync(nullptr, &gerror);
+    if (gerror != nullptr)
     {
       setError(E_GetAuthority, gerror->message);
       g_error_free(gerror);
@@ -181,13 +181,13 @@ void Authority::Private::init()
     }
   }
 
-  if (pkAuthority == NULL)
+  if (pkAuthority == nullptr)
   {
     return;
   }
 
   // connect changed signal
-  g_signal_connect(G_OBJECT(pkAuthority), "changed", G_CALLBACK(pk_config_changed), NULL);
+  g_signal_connect(G_OBJECT(pkAuthority), "changed", G_CALLBACK(pk_config_changed), nullptr);
 }
 
 void Authority::Private::setError(Authority::ErrorCode code, const TQString &details, bool recover)
@@ -271,11 +271,11 @@ Authority::Result Authority::checkAuthorizationSync(const TQString &actionId,
     return Unknown;
   }
 
-  GError *error = NULL;
+  GError *error = nullptr;
   PolkitAuthorizationResult *pk_result = polkit_authority_check_authorization_sync(d->pkAuthority,
-          subject.subject(), actionId.ascii(), NULL, (PolkitCheckAuthorizationFlags)(int)flags,
-          NULL, &error);
-  if (error != NULL)
+          subject.subject(), actionId.ascii(), nullptr, (PolkitCheckAuthorizationFlags)(int)flags,
+          nullptr, &error);
+  if (error != nullptr)
   {
     d->setError(E_CheckFailed, error->message);
     g_error_free(error);
@@ -308,7 +308,7 @@ void Authority::checkAuthorization(const TQString &actionId, const Subject &subj
     return;
   }
 
-  polkit_authority_check_authorization(d->pkAuthority, subject.subject(), actionId.ascii(), NULL,
+  polkit_authority_check_authorization(d->pkAuthority, subject.subject(), actionId.ascii(), nullptr,
           (PolkitCheckAuthorizationFlags)(int)flags, d->m_checkAuthorizationCancellable,
           d->checkAuthorizationCallback, this);
 }
@@ -321,10 +321,10 @@ void Authority::Private::checkAuthorizationCallback(GObject *object, GAsyncResul
     return;
   }
 
-  GError *error = NULL;
+  GError *error = nullptr;
   PolkitAuthorizationResult *pkResult = polkit_authority_check_authorization_finish(
           (PolkitAuthority*)object, result, &error);
-  if (error != NULL)
+  if (error != nullptr)
   {
     // We don't want to set error if this is cancellation of some action
     if (error->code != 1)
@@ -334,7 +334,7 @@ void Authority::Private::checkAuthorizationCallback(GObject *object, GAsyncResul
     g_error_free(error);
     return;
   }
-  if (pkResult != NULL)
+  if (pkResult != nullptr)
   {
     emit authority->checkAuthorizationFinished(polkitResultToResult(pkResult));
     g_object_unref(pkResult);
@@ -360,9 +360,9 @@ ActionDescription::List Authority::enumerateActionsSync()
     return ActionDescription::List();
   }
 
-  GError *error = NULL;
-  GList *glist = polkit_authority_enumerate_actions_sync(d->pkAuthority, NULL, &error);
-  if (error != NULL)
+  GError *error = nullptr;
+  GList *glist = polkit_authority_enumerate_actions_sync(d->pkAuthority, nullptr, &error);
+  if (error != nullptr)
   {
     d->setError(E_EnumFailed, error->message);
     g_error_free(error);
@@ -390,9 +390,9 @@ void Authority::Private::enumerateActionsCallback(GObject *object, GAsyncResult
   {
     return;
   }
-  GError *error = NULL;
+  GError *error = nullptr;
   GList *list = polkit_authority_enumerate_actions_finish((PolkitAuthority*)object, result, &error);
-  if (error != NULL)
+  if (error != nullptr)
   {
     // We don't want to set error if this is cancellation of some action
     if (error->code != 1)
@@ -428,9 +428,9 @@ bool Authority::registerAuthenticationAgentSync(const Subject &subject, const TQ
     return false;
   }
 
-  GError *error = NULL;
+  GError *error = nullptr;
   gboolean result = polkit_authority_register_authentication_agent_sync(d->pkAuthority,
-          subject.subject(), locale.ascii(), objectPath.ascii(), NULL, &error);
+          subject.subject(), locale.ascii(), objectPath.ascii(), nullptr, &error);
   if (error)
   {
     d->setError(E_RegisterFailed, error->message);
@@ -468,9 +468,9 @@ void Authority::Private::registerAuthenticationAgentCallback(GObject *object, GA
   {
     return;
   }
-  GError *error = NULL;
+  GError *error = nullptr;
   bool res = polkit_authority_register_authentication_agent_finish((PolkitAuthority*)object, result, &error);
-  if (error != NULL)
+  if (error != nullptr)
   {
     // We don't want to set error if this is cancellation of some action
     if (error->code != 1)
@@ -505,10 +505,10 @@ bool Authority::unregisterAuthenticationAgentSync(const Subject &subject, const
     return false;
   }
 
-  GError *error = NULL;
+  GError *error = nullptr;
   bool result = polkit_authority_unregister_authentication_agent_sync(d->pkAuthority,
-          subject.subject(), objectPath.utf8().data(), NULL, &error);
-  if (error != NULL)
+          subject.subject(), objectPath.utf8().data(), nullptr, &error);
+  if (error != nullptr)
   {
     d->setError(E_UnregisterFailed, error->message);
     g_error_free(error);
@@ -544,10 +544,10 @@ void Authority::Private::unregisterAuthenticationAgentCallback(GObject *object,
   {
     return;
   }
-  GError *error = NULL;
+  GError *error = nullptr;
   bool res = polkit_authority_unregister_authentication_agent_finish((PolkitAuthority*)object,
           result, &error);
-  if (error != NULL)
+  if (error != nullptr)
   {
     // We don't want to set error if this is cancellation of some action
     if (error->code != 1)
@@ -582,10 +582,10 @@ bool Authority::authenticationAgentResponseSync(const TQString &cookie, const Id
     return false;
   }
 
-  GError *error = NULL;
+  GError *error = nullptr;
   bool result = polkit_authority_authentication_agent_response_sync(d->pkAuthority,
-          cookie.utf8().data(), identity.identity(), NULL, &error);
-  if (error != NULL)
+          cookie.utf8().data(), identity.identity(), nullptr, &error);
+  if (error != nullptr)
   {
     d->setError(E_AgentResponseFailed, error->message);
     g_error_free(error);
@@ -621,10 +621,10 @@ void Authority::Private::authenticationAgentResponseCallback(GObject *object, GA
   {
     return;
   }
-  GError *error = NULL;
+  GError *error = nullptr;
   bool res = polkit_authority_authentication_agent_response_finish((PolkitAuthority*)object, result,
           &error);
-  if (error != NULL)
+  if (error != nullptr)
   {
     // We don't want to set error if this is cancellation of some action
     if (error->code != 1)
@@ -650,10 +650,10 @@ TemporaryAuthorization::List Authority::enumerateTemporaryAuthorizationsSync(con
 {
   TemporaryAuthorization::List result;
 
-  GError *error = NULL;
+  GError *error = nullptr;
   GList *glist = polkit_authority_enumerate_temporary_authorizations_sync(d->pkAuthority,
-          subject.subject(), NULL, &error);
-  if (error != NULL)
+          subject.subject(), nullptr, &error);
+  if (error != nullptr)
   {
     d->setError(E_EnumFailed, error->message);
     g_error_free(error);
@@ -661,7 +661,7 @@ TemporaryAuthorization::List Authority::enumerateTemporaryAuthorizationsSync(con
   }
 
   GList *glist2;
-  for (glist2 = glist; glist2 != NULL; glist2 = g_list_next(glist2))
+  for (glist2 = glist; glist2 != nullptr; glist2 = g_list_next(glist2))
   {
     result.append(TemporaryAuthorization((PolkitTemporaryAuthorization*)glist2->data));
     if (glist2->data)
@@ -682,10 +682,10 @@ void Authority::Private::enumerateTemporaryAuthorizationsCallback(GObject *objec
     return;
   }
 
-  GError *error = NULL;
+  GError *error = nullptr;
   GList *glist = polkit_authority_enumerate_temporary_authorizations_finish((PolkitAuthority*)object,
           result, &error);
-  if (error != NULL)
+  if (error != nullptr)
   {
     // We don't want to set error if this is cancellation of some action
     if (error->code != 1)
@@ -697,7 +697,7 @@ void Authority::Private::enumerateTemporaryAuthorizationsCallback(GObject *objec
   }
   TemporaryAuthorization::List res;
   GList *glist2;
-  for (glist2 = glist; glist2 != NULL; glist2 = g_list_next(glist2))
+  for (glist2 = glist; glist2 != nullptr; glist2 = g_list_next(glist2))
   {
     res.append(TemporaryAuthorization((PolkitTemporaryAuthorization*)glist2->data));
     if (glist2->data)
@@ -724,10 +724,10 @@ bool Authority::revokeTemporaryAuthorizationsSync(const Subject &subject)
     return false;
   }
 
-  GError *error = NULL;
+  GError *error = nullptr;
   bool result = polkit_authority_revoke_temporary_authorizations_sync(d->pkAuthority,
-          subject.subject(), NULL, &error);
-  if (error != NULL)
+          subject.subject(), nullptr, &error);
+  if (error != nullptr)
   {
     d->setError(E_RevokeFailed, error->message);
     g_error_free(error);
@@ -757,9 +757,9 @@ void Authority::Private::revokeTemporaryAuthorizationsCallback(GObject *object,
     return;
   }
 
-  GError *error = NULL;
+  GError *error = nullptr;
   bool res = polkit_authority_revoke_temporary_authorizations_finish((PolkitAuthority*)object, result, &error);
-  if (error != NULL)
+  if (error != nullptr)
   {
     // We don't want to set error if this is cancellation of some action
     if (error->code != 1)
@@ -788,10 +788,10 @@ bool Authority::revokeTemporaryAuthorizationSync(const TQString &id)
     return false;
   }
 
-  GError *error = NULL;
+  GError *error = nullptr;
   bool result =  polkit_authority_revoke_temporary_authorization_by_id_sync(d->pkAuthority,
-          id.utf8().data(), NULL, &error);
-  if (error != NULL)
+          id.utf8().data(), nullptr, &error);
+  if (error != nullptr)
   {
     d->setError(E_RevokeFailed, error->message);
     g_error_free(error);
@@ -821,10 +821,10 @@ void Authority::Private::revokeTemporaryAuthorizationCallback(GObject *object,
     return;
   }
 
-  GError *error = NULL;
+  GError *error = nullptr;
   bool res = polkit_authority_revoke_temporary_authorization_by_id_finish((PolkitAuthority*)object,
           result, &error);
-  if (error != NULL)
+  if (error != nullptr)
   {
     // We don't want to set error if this is cancellation of some action
     if (error->code != 1)
diff --git a/core/polkit-tqt-authority.h b/core/polkit-tqt-authority.h
index 4df6a8a02..d4e0e0b53 100644
--- a/core/polkit-tqt-authority.h
+++ b/core/polkit-tqt-authority.h
@@ -137,7 +137,7 @@ class POLKIT_TQT_EXPORT Authority : public TQObject
      *
      * \return The current authority instance
      */
-    static Authority* instance(PolkitAuthority *authority = NULL);
+    static Authority* instance(PolkitAuthority *authority = nullptr);
 
     ~Authority();
 
@@ -513,7 +513,7 @@ class POLKIT_TQT_EXPORT Authority : public TQObject
     Authority(const Authority&);
     Authority& operator=(const Authority&);
 
-    Authority(TQObject *parent = NULL);
+    Authority(TQObject *parent = nullptr);
 
     static Authority *m_theAuthority;
 
diff --git a/core/polkit-tqt-details.cpp b/core/polkit-tqt-details.cpp
index 245ce2577..5b2a80d64 100644
--- a/core/polkit-tqt-details.cpp
+++ b/core/polkit-tqt-details.cpp
@@ -37,7 +37,7 @@ namespace PolkitTQt
 class Details::Data : public TQShared
 {
   public:
-    Data() : details(NULL)
+    Data() : details(nullptr)
     {
     }
 
@@ -111,7 +111,7 @@ Details::~Details()
 TQString Details::lookup(const TQString &key) const
 {
   const gchar *result = polkit_details_lookup(d->details, key.utf8().data());
-  if (result != NULL)
+  if (result != nullptr)
   {
     return TQString::fromUtf8(result);
   }
diff --git a/core/polkit-tqt-identity.cpp b/core/polkit-tqt-identity.cpp
index 1415d5d7f..713c61c37 100644
--- a/core/polkit-tqt-identity.cpp
+++ b/core/polkit-tqt-identity.cpp
@@ -36,7 +36,7 @@ namespace PolkitTQt
 class Identity::Data : public TQShared
 {
   public:
-    Data() : identity(NULL)
+    Data() : identity(nullptr)
     {
     }
 
@@ -108,7 +108,7 @@ Identity::~Identity()
 
 bool Identity::isValid() const
 {
-  return (d->identity != NULL);
+  return (d->identity != nullptr);
 }
 
 PolkitIdentity* Identity::identity() const
@@ -149,9 +149,9 @@ Identity Identity::fromString(const TQString &string)
     return Identity();
   }
 
-  GError *error = NULL;
+  GError *error = nullptr;
   PolkitIdentity *poliden = polkit_identity_from_string(string.utf8().data(), &error);
-  if (error != NULL)
+  if (error != nullptr)
   {
     tqWarning(TQString("Cannot create valid Identity from string: %1").arg(error->message));
     return Identity();
@@ -166,12 +166,12 @@ Identity Identity::fromString(const TQString &string)
 
 UnixUserIdentity::UnixUserIdentity(const TQString &name) : Identity()
 {
-  GError *error = NULL;
+  GError *error = nullptr;
   setIdentity(polkit_unix_user_new_for_name(name.utf8().data(), &error));
-  if (error != NULL)
+  if (error != nullptr)
   {
     tqWarning(TQString("Cannot create UnixUserIdentity: %1").arg(error->message));
-    setIdentity(NULL);
+    setIdentity(nullptr);
   }
 }
 
@@ -201,12 +201,12 @@ void UnixUserIdentity::setUid(uid_t uid)
 
 UnixGroupIdentity::UnixGroupIdentity(const TQString &name) : Identity()
 {
-  GError *error = NULL;
+  GError *error = nullptr;
   setIdentity(polkit_unix_group_new_for_name(name.utf8().data(), &error));
-  if (error != NULL)
+  if (error != nullptr)
   {
     tqWarning(TQString("Cannot create UnixGroupIdentity: %1").arg(error->message));
-    setIdentity(NULL);
+    setIdentity(nullptr);
   }
 }
 
diff --git a/core/polkit-tqt-subject.cpp b/core/polkit-tqt-subject.cpp
index 3d9e99b7a..fe51e5265 100644
--- a/core/polkit-tqt-subject.cpp
+++ b/core/polkit-tqt-subject.cpp
@@ -36,7 +36,7 @@ namespace PolkitTQt
 class Subject::Data : public TQShared
 {
   public:
-    Data() : subject(NULL)
+    Data() : subject(nullptr)
     {
     }
 
@@ -108,7 +108,7 @@ Subject::~Subject()
 
 bool Subject::isValid() const
 {
-  return (d->subject != NULL);
+  return (d->subject != nullptr);
 }
 
 PolkitSubject* Subject::subject() const
@@ -149,9 +149,9 @@ Subject Subject::fromString(const TQString &string)
     return Subject();
   }
 
-  GError *error = NULL;
+  GError *error = nullptr;
   PolkitSubject *polsub = polkit_subject_from_string(string.utf8().data(), &error);
-  if (error != NULL)
+  if (error != nullptr)
   {
     tqWarning(TQString("Cannot create valid Subject from string: %1").arg(error->message));
     return Subject();
@@ -229,12 +229,12 @@ UnixSessionSubject::UnixSessionSubject(const TQString &sessionId) : Subject()
 
 UnixSessionSubject::UnixSessionSubject(TQ_LONG pid) : Subject()
 {
-  GError *error = NULL;
-  setSubject(polkit_unix_session_new_for_process_sync(pid, NULL, &error));
-  if (error != NULL)
+  GError *error = nullptr;
+  setSubject(polkit_unix_session_new_for_process_sync(pid, nullptr, &error));
+  if (error != nullptr)
   {
     tqWarning(TQString("Cannot create unix session subject from pid: %1").arg(error->message));
-    setSubject(NULL);
+    setSubject(nullptr);
   }
 }
 
diff --git a/examples/PkExample.cpp b/examples/PkExample.cpp
index 4491dadd3..99c0e641f 100644
--- a/examples/PkExample.cpp
+++ b/examples/PkExample.cpp
@@ -48,12 +48,12 @@ using namespace PolkitTQt;
 using namespace PolkitTQt::Gui;
 
 
-PkExample::PkExample() : TQMainWindow(0, "Polkit tqt example application", WDestructiveClose)
+PkExample::PkExample() : TQMainWindow(nullptr, "Polkit tqt example application", WDestructiveClose)
 {
   TQWidget *privateLayoutWidget = new TQWidget(this, "qt_central_widget");
   setCentralWidget(privateLayoutWidget);
 
-  grid = new TQGridLayout(0, 9, 1, 0, 6, "grid");
+  grid = new TQGridLayout(nullptr, 9, 1, 0, 6, "grid");
   grid->setColSpacing(0, 700);
   grid->setColSpacing(1, 200);
 
diff --git a/examples/agent/tqtlistener.cpp b/examples/agent/tqtlistener.cpp
index e915eabce..59cfd40f2 100644
--- a/examples/agent/tqtlistener.cpp
+++ b/examples/agent/tqtlistener.cpp
@@ -42,17 +42,14 @@ void TQtListener::initiateAuthentication(const TQString &actionId, const TQStrin
   tqDebug("Initiate authentication for " + actionId + " with message " + message);
   tqDebug("    iconName " + iconName);
   TQStringList dkeys = details.keys();
-  TQStringList::Iterator dkIt;
-  for (dkIt = dkeys.begin(); dkIt != dkeys.end(); ++dkIt)
+  for (const TQString &dkey : dkeys)
   {
-    tqDebug("    key " + (*dkIt));
+    tqDebug("    key " + dkey);
   }
   tqDebug("    cookie " + cookie);
 
-  PolkitTQt::Identity::List::ConstIterator iIt;
-  for (iIt = identities.begin(); iIt != identities.end(); ++iIt)
+  for (const PolkitTQt::Identity &identity : identities)
   {
-    PolkitTQt::Identity identity = *iIt;
     tqDebug(identity.toString());
     Session *session = new Session(identity, cookie, result);
     connect(session, TQT_SIGNAL(request(const TQString&, bool)), this,
@@ -83,7 +80,7 @@ void TQtListener::request(const TQString &request, bool echo)
   Session *session = (Session*)sender();
   bool ok;
   TQString text = TQInputDialog::getText("TQt Agent", "Enter authorization password:",
-      TQLineEdit::Password, TQString::null, &ok, NULL );
+      TQLineEdit::Password, TQString::null, &ok, nullptr );
   if (ok && !text.isEmpty())
   {
     session->setResponse(text);
diff --git a/examples/agent/tqtlistener.h b/examples/agent/tqtlistener.h
index 202efa278..420915839 100644
--- a/examples/agent/tqtlistener.h
+++ b/examples/agent/tqtlistener.h
@@ -40,7 +40,7 @@ class TQtListener : public PolkitTQt::Agent::Listener
   Q_OBJECT
 
   public:
-    TQtListener(TQObject *parent = 0);
+    TQtListener(TQObject *parent = nullptr);
 
   public slots:
     void initiateAuthentication(const TQString &actionId, const TQString &message,
diff --git a/gui/polkit-tqt-gui-action.h b/gui/polkit-tqt-gui-action.h
index 4f5bb2e2d..21c10100b 100644
--- a/gui/polkit-tqt-gui-action.h
+++ b/gui/polkit-tqt-gui-action.h
@@ -77,7 +77,7 @@ class POLKIT_TQT_EXPORT Action : public TQAction
      * \param actionId the PolicyKit action Id (e.g.: org.freedesktop.policykit.read)
      * \param parent the object parent
      */
-    explicit Action(const TQString& actionId = TQString::null, TQObject *parent = 0);
+    explicit Action(const TQString& actionId = TQString::null, TQObject *parent = nullptr);
 
     ~Action();
 
diff --git a/gui/polkit-tqt-gui-actionbutton.cpp b/gui/polkit-tqt-gui-actionbutton.cpp
index ffcdc2f28..48a0d1494 100644
--- a/gui/polkit-tqt-gui-actionbutton.cpp
+++ b/gui/polkit-tqt-gui-actionbutton.cpp
@@ -92,10 +92,8 @@ void ActionButton::streamClicked()
 
 void ActionButton::updateButton()
 {
-  TQValueList<TQButton*>::iterator butIt;
-  for (butIt = d->buttons.begin(); butIt != d->buttons.end(); ++butIt)
+  for (TQButton *&ent : d->buttons)
   {
-    TQButton *ent = *butIt;
     if (isVisible())
     {
       ent->show();
@@ -128,10 +126,8 @@ void ActionButton::updateButton()
 bool ActionButton::activate()
 {
   bool tg = false;
-  TQValueList<TQButton*>::iterator butIt;
-  for (butIt = d->buttons.begin(); butIt != d->buttons.end(); ++butIt)
+  for (TQButton *&ent : d->buttons)
   {
-    TQButton *ent = *butIt;
     if (ent->isToggleButton())
     {
       // we set the the current Action state
diff --git a/gui/polkit-tqt-gui-actionbutton.h b/gui/polkit-tqt-gui-actionbutton.h
index 7ec45f296..6ab25577c 100644
--- a/gui/polkit-tqt-gui-actionbutton.h
+++ b/gui/polkit-tqt-gui-actionbutton.h
@@ -72,7 +72,7 @@ class POLKIT_TQT_EXPORT ActionButton : public Action
      * \param parent the parent object
      */
     explicit ActionButton(TQButton *button, const TQString &actionId = TQString::null,
-            TQObject *parent = 0);
+            TQObject *parent = nullptr);
     virtual ~ActionButton();
 
     /**
@@ -131,7 +131,7 @@ class POLKIT_TQT_EXPORT ActionButton : public Action
     void clicked(TQButton *button, bool checked = false);
 
   protected:
-    ActionButton(ActionButtonPrivate &dd, const TQString &actionId, TQObject *parent = 0);
+    ActionButton(ActionButtonPrivate &dd, const TQString &actionId, TQObject *parent = nullptr);
 
     ActionButtonPrivate *const d;
 
diff --git a/gui/polkit-tqt-gui-actionbuttons.cpp b/gui/polkit-tqt-gui-actionbuttons.cpp
index 78aced5d6..f4e72d54f 100644
--- a/gui/polkit-tqt-gui-actionbuttons.cpp
+++ b/gui/polkit-tqt-gui-actionbuttons.cpp
@@ -32,7 +32,7 @@ namespace PolkitTQt
 namespace Gui
 {
 
-ActionButtons::ActionButtons(const TQValueList<TQButton*> &buttons, const TQString &actionId,
+ActionButtons::ActionButtons(TQValueList<TQButton*> &buttons, const TQString &actionId,
         TQObject *parent) : ActionButton(*new ActionButtonPrivate(), actionId, parent)
 {
   setButtons(buttons);
@@ -42,17 +42,15 @@ ActionButtons::~ActionButtons()
 {
 }
 
-void ActionButtons::setButtons(const TQValueList<TQButton*> &buttons)
+void ActionButtons::setButtons(TQValueList<TQButton*> &buttons)
 {
-  TQValueList<TQButton*>::iterator butIt;
-  for (butIt = d->buttons.begin(); butIt != d->buttons.end(); ++butIt)
+  for (TQButton *&ent : buttons)
   {
-    TQButton *ent = *butIt;
     addButton(ent);
   }
 }
 
-TQValueList<TQButton *> ActionButtons::buttons() const
+TQValueList<TQButton*> ActionButtons::buttons() const
 {
   return d->buttons;
 }
diff --git a/gui/polkit-tqt-gui-actionbuttons.h b/gui/polkit-tqt-gui-actionbuttons.h
index b85b632be..43b80bb93 100644
--- a/gui/polkit-tqt-gui-actionbuttons.h
+++ b/gui/polkit-tqt-gui-actionbuttons.h
@@ -62,8 +62,8 @@ class ActionButtons : public ActionButton
      * \param actionId the action Id to create the underlying Action
      * \param parent the parent object
      */
-    explicit ActionButtons(const TQValueList<TQButton*> &buttons,
-            const TQString &actionId = TQString::null, TQObject *parent = 0);
+    explicit ActionButtons(TQValueList<TQButton*> &buttons,
+            const TQString &actionId = TQString::null, TQObject *parent = nullptr);
     virtual ~ActionButtons();
 
     /**
@@ -80,7 +80,7 @@ class ActionButtons : public ActionButton
      *
      * \param buttons the new buttons associated with the underlying action
      */
-    void setButtons(const TQValueList<TQButton*> &buttons);
+    void setButtons(TQValueList<TQButton*> &buttons);
 
     /**
      * Returns the current buttons list
diff --git a/tests/test_auth_enum_actions.cpp b/tests/test_auth_enum_actions.cpp
index d7c992a97..8a9030ff7 100644
--- a/tests/test_auth_enum_actions.cpp
+++ b/tests/test_auth_enum_actions.cpp
@@ -27,12 +27,11 @@ int main(void)
   }
   // Check whether enumerateAction returns at least example actions
   int count = 0;
-  ActionDescription::List::const_iterator adIt;
-  for (adIt = list.begin(); adIt != list.end(); ++adIt)
+  for (const ActionDescription &actionDesc : list)
   {
-    if (((*adIt).actionId() == "org.tqt.policykit.examples.kick") ||
-        ((*adIt).actionId() == "org.tqt.policykit.examples.cry") ||
-        ((*adIt).actionId() == "org.tqt.policykit.examples.bleed"))
+    if ((actionDesc.actionId() == "org.tqt.policykit.examples.kick") ||
+        (actionDesc.actionId() == "org.tqt.policykit.examples.cry") ||
+        (actionDesc.actionId() == "org.tqt.policykit.examples.bleed"))
     {
       count++;
     }