diff --git a/src/ATC/ATISEncoder.cxx b/src/ATC/ATISEncoder.cxx
index 7b63f104a..1bec44ca9 100644
--- a/src/ATC/ATISEncoder.cxx
+++ b/src/ATC/ATISEncoder.cxx
@@ -45,7 +45,7 @@ string ATCSpeech::getSpokenNumber( string number )
 {
   string result;
   for( string::iterator it = number.begin(); it != number.end(); ++it ) {
-    if( false == result.empty() )
+    if( !result.empty() )
       result.SPACE;
     result.append( getSpokenDigit( (*it) - '0' ));
   }
@@ -79,8 +79,8 @@ string ATCSpeech::getSpokenNumber( int number, bool leadingZero, int digits )
     result.append( globals->get_locale()->getLocalizedString("minus", "atc", "minus" ) );
   }
 
-  while( false == spokenDigits.empty() ) {
-    if( false == result.empty() )
+  while( !spokenDigits.empty() ) {
+    if( !result.empty() )
       result.SPACE;
 
     result.append( spokenDigits.back() );
@@ -157,7 +157,7 @@ SGPropertyNode_ptr findAtisTemplate( const std::string & stationId, SGPropertyNo
   for( PropertyList::iterator asit = schemaNodes.begin(); asit != schemaNodes.end(); ++asit ) {
     SGPropertyNode_ptr ppp = (*asit)->getNode("station-starts-with", false );
     atisTemplate = (*asit)->getNode("atis", false );
-    if( false == atisTemplate.valid() ) continue; // no <atis> node - ignore entry
+    if( !atisTemplate.valid() ) continue; // no <atis> node - ignore entry
 
     PropertyList startsWithNodes = (*asit)->getChildren("station-starts-with");
     for( PropertyList::iterator swit = startsWithNodes.begin(); swit != startsWithNodes.end(); ++swit ) {
@@ -176,10 +176,10 @@ string ATISEncoder::encodeATIS( ATISInformationProvider * atisInformation )
 {
   using simgear::strutils::lowercase;
 
-  if( false == atisInformation->isValid() ) return NO_ATIS;
+  if( !atisInformation->isValid() ) return NO_ATIS;
 
   airport = FGAirport::getByIdent( atisInformation->airportId() );
-  if( false == airport.valid() ) {
+  if( !airport.valid() ) {
     SG_LOG( SG_ATC, SG_WARN, "ATISEncoder: unknown airport id " << atisInformation->airportId() );
     return NO_ATIS;
   }
@@ -187,7 +187,7 @@ string ATISEncoder::encodeATIS( ATISInformationProvider * atisInformation )
   _atis = atisInformation;
 
   // lazily load the schema file on the first call
-  if( false == atisSchemaNode.valid() ) {
+  if( !atisSchemaNode.valid() ) {
     atisSchemaNode = new SGPropertyNode();
     try
     {
@@ -204,7 +204,7 @@ string ATISEncoder::encodeATIS( ATISInformationProvider * atisInformation )
   string stationId = lowercase( airport->ident() );
   
   SGPropertyNode_ptr atisTemplate = findAtisTemplate( stationId, atisSchemaNode );;
-  if( false == atisTemplate.valid() ) {
+  if( !atisTemplate.valid() ) {
     SG_LOG(SG_ATC, SG_WARN, "no matching atis template for station " << stationId  );
     return NO_ATIS; // no template for this station!?
   }
@@ -324,7 +324,7 @@ string ATISEncoder::processIfToken( SGPropertyNode_ptr token )
 bool ATISEncoder::checkEmptyCondition( SGPropertyNode_ptr node, bool isEmpty ) 
 {
   SGPropertyNode_ptr n1 = node->getNode( "token", false );
-  if( false == n1.valid() ) {
+  if( !n1.valid() ) {
       SG_LOG(SG_ATC, SG_WARN, "missing <token> node for (not)-empty"  );
       return false;
   }
@@ -526,7 +526,7 @@ string ATISEncoder::getClouds( SGPropertyNode_ptr )
   ATISInformationProvider::CloudEntries cloudEntries = _atis->getClouds();
 
   for( ATISInformationProvider::CloudEntries::iterator it = cloudEntries.begin(); it != cloudEntries.end(); it++ ) {
-    if( false == reply.empty() ) reply.SPACE;
+    if( !reply.empty() ) reply.SPACE;
     reply.append( it->second ).SPACE.append( getSpokenAltitude(it->first).SPACE.append( FEET ) );
   }
   return reply;
@@ -539,7 +539,7 @@ string ATISEncoder::getCloudsBrief( SGPropertyNode_ptr )
   ATISInformationProvider::CloudEntries cloudEntries = _atis->getClouds();
 
   for( ATISInformationProvider::CloudEntries::iterator it = cloudEntries.begin(); it != cloudEntries.end(); it++ ) {
-    if( false == reply.empty() ) reply.append(",").SPACE;
+    if( !reply.empty() ) reply.append(",").SPACE;
     reply.append( it->second ).SPACE.append( getSpokenAltitude(it->first) );
   }
   return reply;
diff --git a/src/Environment/metarproperties.cxx b/src/Environment/metarproperties.cxx
index f2ea120e2..568532bbb 100644
--- a/src/Environment/metarproperties.cxx
+++ b/src/Environment/metarproperties.cxx
@@ -244,7 +244,7 @@ void MetarProperties::setMetar( SGSharedPtr<FGMetar> m )
     
     const vector<string> weather = m->getWeather();
     for( vector<string>::const_iterator it = weather.begin(); it != weather.end(); ++it ) {
-        if( false == _decoded.empty() ) _decoded.append(", ");
+        if( !_decoded.empty() ) _decoded.append(", ");
         _decoded.append(*it);
     }
 
@@ -351,7 +351,7 @@ void MetarProperties::setMetar( SGSharedPtr<FGMetar> m )
 
         // fog/mist/haze cloud layer does not work with 3d clouds yet :-(
         bool setGroundCloudLayer = _rootNode->getBoolValue("set-ground-cloud-layer", false ) &&
-              false == fgGetBool("/sim/rendering/clouds3d-enable", false);
+              !fgGetBool("/sim/rendering/clouds3d-enable", false);
 
         if( setGroundCloudLayer ) {
             // create a cloud layer #0 starting at the ground if its fog, mist or haze
diff --git a/src/Environment/realwx_ctrl.cxx b/src/Environment/realwx_ctrl.cxx
index ce7d54eb0..cfcf72007 100644
--- a/src/Environment/realwx_ctrl.cxx
+++ b/src/Environment/realwx_ctrl.cxx
@@ -356,7 +356,7 @@ BasicRealWxController::MetarPropertiesList::iterator BasicRealWxController::find
   // don not compare unprocessed property path
   // /foo/bar[0]/baz equals /foo/bar/baz
   SGPropertyNode_ptr n = fgGetNode(propPath,false);
-  if( false == n.valid() ) // trivial: node does not exist
+  if( !n.valid() ) // trivial: node does not exist
     return _metarProperties.end();
 
   MetarPropertiesList::iterator it = _metarProperties.begin();
diff --git a/src/Environment/ridge_lift.cxx b/src/Environment/ridge_lift.cxx
index f1315fe0b..872a33a14 100644
--- a/src/Environment/ridge_lift.cxx
+++ b/src/Environment/ridge_lift.cxx
@@ -112,7 +112,7 @@ void FGRidgeLift::update(double dt) {
 	if( dt <= SGLimitsd::min() ) // paused, do nothing but keep current lift
 		return;
 
-	if( _enabled_node && false == _enabled_node->getBoolValue() ) {
+	if( _enabled_node && !_enabled_node->getBoolValue() ) {
 		// do nothing if lift has been zeroed
 		if( strength != 0.0 ) {
 			if( strength > 0.1 ) {
diff --git a/src/Instrumentation/commradio.cxx b/src/Instrumentation/commradio.cxx
index 7d6c11b54..38c3f0b3a 100644
--- a/src/Instrumentation/commradio.cxx
+++ b/src/Instrumentation/commradio.cxx
@@ -315,7 +315,7 @@ void MetarBridge::requestMetarForId(std::string & id)
     _metarPropertiesNode->getNode("time-to-live", true)->setDoubleValue(0.0);
   } else {
     // use the present weather to generate the ATIS.
-    if ( NULL != _atisNode && false == _requestedId.empty()) {
+    if ( NULL != _atisNode && !_requestedId.empty()) {
       CurrentWeatherATISInformationProvider provider(_requestedId);
       _atisNode->setStringValue(_atisEncoder.encodeATIS(&provider));
     }
@@ -331,7 +331,7 @@ void MetarBridge::clearMetar()
 void MetarBridge::valueChanged(SGPropertyNode * node)
 {
   // check for raising edge of valid flag
-  if ( NULL == node || false == node->getBoolValue() || false == _realWxEnabledNode->getBoolValue()) return;
+  if ( NULL == node || !node->getBoolValue() || !_realWxEnabledNode->getBoolValue()) return;
 
   std::string responseId = simgear::strutils::uppercase(_metarPropertiesNode->getNode("station-id", true)->getStringValue());
 
@@ -640,7 +640,7 @@ void CommRadioImpl::update(double dt)
     _commStationForFrequency = flightgear::CommStation::findByFreq(freqKhz, position, NULL);
   }
 
-  if (false == _commStationForFrequency.valid()) {
+  if (!_commStationForFrequency.valid()) {
     stopAudio();
     return;
   }
diff --git a/src/Instrumentation/dme.cxx b/src/Instrumentation/dme.cxx
index 8bc183b9a..3173d932a 100644
--- a/src/Instrumentation/dme.cxx
+++ b/src/Instrumentation/dme.cxx
@@ -195,7 +195,7 @@ DME::update (double delta_time_sec)
 
     if (distance_nm <= range_nm) {
         double volume = _volume_node->getDoubleValue();
-        if( false == _ident_btn_node->getBoolValue() )
+        if( !_ident_btn_node->getBoolValue() )
             volume = 0.0;
 
         _audioIdent->setIdent(_navrecord->ident(), volume );
diff --git a/src/Instrumentation/mag_compass.cxx b/src/Instrumentation/mag_compass.cxx
index 97586b59b..44d8d30d2 100644
--- a/src/Instrumentation/mag_compass.cxx
+++ b/src/Instrumentation/mag_compass.cxx
@@ -30,7 +30,7 @@ MagCompass::MagCompass ( SGPropertyNode *node )
         _deviation_table = new SGInterpTable( deviation_table_node );
       } else {
         std::string deviation_node_name = n->getStringValue();
-        if( false == deviation_node_name.empty() )
+        if( !deviation_node_name.empty() )
           _deviation_node = fgGetNode( deviation_node_name, true );
       }
     }
diff --git a/src/Instrumentation/newnavradio.cxx b/src/Instrumentation/newnavradio.cxx
index 05fa47322..9ea9e2bc7 100644
--- a/src/Instrumentation/newnavradio.cxx
+++ b/src/Instrumentation/newnavradio.cxx
@@ -218,7 +218,7 @@ void NavRadioComponentWithIdent::update( double dt, const SGGeod & aircraftPosit
   NavRadioComponent::update( dt, aircraftPosition );
   _audioIdent->update( dt );
 
-  if( false == ( valid() && _identEnabled && _signalQuality_norm > 0.1 ) ) {
+  if( !( valid() && _identEnabled && _signalQuality_norm > 0.1 ) ) {
       _audioIdent->setIdent("", 0.0 );
       return;
   }
@@ -273,7 +273,7 @@ void NavRadioComponent::search( double frequency, const SGGeod & aircraftPositio
 
 double NavRadioComponent::computeSignalQuality_norm( const SGGeod & aircraftPosition )
 {
-  if( false == valid() ) return 0.0;
+  if( !valid() ) return 0.0;
 
   double distance_nm = _slantDistance_m * SG_METER_TO_NM;
   double range_nm = _range_nm;
@@ -286,7 +286,7 @@ double NavRadioComponent::computeSignalQuality_norm( const SGGeod & aircraftPosi
 
 void NavRadioComponent::update( double dt, const SGGeod & aircraftPosition )
 {
-    if( false == valid() ) {
+    if( !valid() ) {
       _signalQuality_norm = 0.0;
       _trueBearingTo_deg = 0.0;
       _trueBearingFrom_deg = 0.0;
@@ -426,7 +426,7 @@ void VOR::update( double dt, const SGGeod & aircraftPosition )
   _totalTime += dt;
   NavRadioComponentWithIdent::update( dt, aircraftPosition );
 
-  if( false == valid() ) {
+  if( !valid() ) {
       _radial = 0.0;
       return;
   }
@@ -448,7 +448,7 @@ void VOR::update( double dt, const SGGeod & aircraftPosition )
 
 void VOR::display( NavIndicator & navIndicator )
 {
-  if( false == valid() ) return;
+  if( !valid() ) return;
 
   double offset = SGMiscd::normalizePeriodic(-180.0,180.0,_radial - navIndicator.getSelectedCourse());
   bool to = fabs(offset) >= 90.0;
@@ -549,7 +549,7 @@ FGNavList::TypeFilter* LOC::getNavaidFilter()
 void LOC::search( double frequency, const SGGeod & aircraftPosition )
 {
   NavRadioComponentWithIdent::search( frequency, aircraftPosition );
-  if( false == valid() ) {
+  if( !valid() ) {
       _localizerWidth_deg = 0.0;
       return;
   }
@@ -587,7 +587,7 @@ void LOC::update( double dt, const SGGeod & aircraftPosition )
 {
   NavRadioComponentWithIdent::update( dt, aircraftPosition );
 
-  if( false == valid() ) {
+  if( !valid() ) {
     _localizerOffset_norm = 0.0;
     _localizerOffset_m = 0.0;
     return;
@@ -611,7 +611,7 @@ void LOC::update( double dt, const SGGeod & aircraftPosition )
 
 void LOC::display( NavIndicator & navIndicator )
 {
-  if( false == valid() ) 
+  if( !valid() ) 
     return;
 
   navIndicator.showTo( true );
@@ -738,7 +738,7 @@ SGVec3d GS::tangentVector(const SGGeod& midpoint, const double heading)
 void GS::search( double frequency, const SGGeod & aircraftPosition )
 {
   NavRadioComponent::search( frequency, aircraftPosition );
-  if( false == valid() ) {
+  if( !valid() ) {
       _gsAxis = SGVec3d::zeros();
       _gsVertical = SGVec3d::zeros();
       _targetGlideslope_deg = 3.0;
@@ -759,7 +759,7 @@ void GS::search( double frequency, const SGGeod & aircraftPosition )
 void GS::update( double dt, const SGGeod & aircraftPosition )
 {
   NavRadioComponent::update( dt, aircraftPosition );
-  if( false == valid() ) {
+  if( !valid() ) {
       _glideslopeOffset_norm = 0.0;
       return;
   }
@@ -785,7 +785,7 @@ void GS::update( double dt, const SGGeod & aircraftPosition )
   double offset = _targetGlideslope_deg - gsDirect;
   if( offset < 0.0 )
     offset = _targetGlideslope_deg/2 * sawtooth(2.0*offset/_targetGlideslope_deg);
-    assert( false == SGMisc<double>::isNaN(offset) );
+    assert( !SGMisc<double>::isNaN(offset) );
 // GS is documented to be 1.4 degrees thick, 
 // i.e. plus or minus 0.7 degrees from the midline:
   _glideslopeOffset_norm = SGMiscd::clip(offset/0.7, -1.0, 1.0);
@@ -793,7 +793,7 @@ void GS::update( double dt, const SGGeod & aircraftPosition )
 
 void GS::display( NavIndicator & navIndicator )
 {
-  if( false == valid() ) {
+  if( !valid() ) {
     navIndicator.setGS( false );
     return;
   }
@@ -913,7 +913,7 @@ void NavRadioImpl::update( double dt )
           p->search( _frequency, position );
       p->update( dt, position );
 
-      if( false == _cdiDisconnected )
+      if( !_cdiDisconnected )
           p->display( _navIndicator );
   }
 
diff --git a/src/Network/http/FlightHistoryUriHandler.cxx b/src/Network/http/FlightHistoryUriHandler.cxx
index ee8ea43d6..41d69a768 100644
--- a/src/Network/http/FlightHistoryUriHandler.cxx
+++ b/src/Network/http/FlightHistoryUriHandler.cxx
@@ -116,7 +116,7 @@ static string AutoUpdateResponse(const HTTPRequest & request,
 static string FlightHistoryToKml(const SGGeodVec & history,
 		const HTTPRequest & request) {
 	string interval = request.RequestVariables.get("interval");
-	if (false == interval.empty()) {
+	if (!interval.empty()) {
 		return AutoUpdateResponse(request, "/flighthistory/track.kml", interval);
 	}
 
diff --git a/src/Network/http/JsonUriHandler.cxx b/src/Network/http/JsonUriHandler.cxx
index 6b0187ba1..c0c93fa8c 100644
--- a/src/Network/http/JsonUriHandler.cxx
+++ b/src/Network/http/JsonUriHandler.cxx
@@ -50,7 +50,7 @@ bool JsonUriHandler::handleRequest( const HTTPRequest & request, HTTPResponse &
     bool timestamp = request.RequestVariables.get("t") == "y";
 
     SGPropertyNode_ptr node = getRequestedNode(request );
-    if( false == node.valid() ) {
+    if( !node.valid() ) {
       response.StatusCode = 404;
       response.Content = "{}";
       return true;
@@ -63,7 +63,7 @@ bool JsonUriHandler::handleRequest( const HTTPRequest & request, HTTPResponse &
 
   if( request.Method == "POST" ) {
     SGPropertyNode_ptr node = getRequestedNode(request );
-    if( false == node.valid() ) {
+    if( !node.valid() ) {
       response.StatusCode = 404;
       response.Content = "{}";
       return true;
@@ -95,11 +95,11 @@ SGPropertyNode_ptr JsonUriHandler::getRequestedNode(const HTTPRequest & request)
   propertyPath = propertyPath.substr( getUri().size() );
 
   // skip trailing '/' - not very efficient but shouldn't happen too often
-  while( false == propertyPath.empty() && propertyPath[ propertyPath.length()-1 ] == '/' )
+  while( !propertyPath.empty() && propertyPath[ propertyPath.length()-1 ] == '/' )
     propertyPath = propertyPath.substr(0,propertyPath.length()-1);
 
   SGPropertyNode_ptr reply = fgGetNode( string("/") + propertyPath );
-  if( false == reply.valid() ) {
+  if( !reply.valid() ) {
     SG_LOG(SG_NETWORK,SG_WARN, "JsonUriHandler: requested node not found: '" << propertyPath << "'");
   }
   return reply;
diff --git a/src/Network/http/PropertyChangeObserver.cxx b/src/Network/http/PropertyChangeObserver.cxx
index b15a18947..5a0bd6787 100644
--- a/src/Network/http/PropertyChangeObserver.cxx
+++ b/src/Network/http/PropertyChangeObserver.cxx
@@ -40,13 +40,13 @@ void PropertyChangeObserver::check()
 {
 
   for (Entries_t::iterator it = _entries.begin(); it != _entries.end(); ++it) {
-    if (false == (*it)->_node.isShared()) {
+    if (!(*it)->_node.isShared()) {
       // node is no longer used but by us - remove the entry
       it = _entries.erase(it);
       continue;
     }
 
-    if( false == (*it)->_changed ) {
+    if(!(*it)->_changed ) {
       (*it)->_changed = (*it)->_prevValue != (*it)->_node->getStringValue();
       if ((*it)->_changed)
         (*it)->_prevValue = (*it)->_node->getStringValue();
diff --git a/src/Network/http/PropertyUriHandler.cxx b/src/Network/http/PropertyUriHandler.cxx
index bdb5de00d..278de44d7 100644
--- a/src/Network/http/PropertyUriHandler.cxx
+++ b/src/Network/http/PropertyUriHandler.cxx
@@ -216,7 +216,7 @@ bool PropertyUriHandler::handleGetRequest( const HTTPRequest & request, HTTPResp
   }
 
   // skip trailing '/' - not very efficient but shouldn't happen too often
-  while( false == propertyPath.empty() && propertyPath[ propertyPath.length()-1 ] == '/' )
+  while( !propertyPath.empty() && propertyPath[ propertyPath.length()-1 ] == '/' )
     propertyPath = propertyPath.substr(0,propertyPath.length()-1);
 
   if( request.RequestVariables.get("submit") == "update" ) {
@@ -273,7 +273,7 @@ bool PropertyUriHandler::handleGetRequest( const HTTPRequest & request, HTTPResp
   catch( string & s ) { 
     SG_LOG(SG_NETWORK,SG_WARN, "httpd: reading '" << propertyPath  << "' failed: " << s );
   }
-  if( false == node.valid() ) {
+  if( !node.valid() ) {
     DOMNode * headline = new DOMNode( "h3" );
     body->addChild( headline );
     headline->addChild( new DOMTextElement( "Non-existent node requested!" ) );
diff --git a/src/Network/http/ScreenshotUriHandler.cxx b/src/Network/http/ScreenshotUriHandler.cxx
index 4f2a1731c..312169144 100644
--- a/src/Network/http/ScreenshotUriHandler.cxx
+++ b/src/Network/http/ScreenshotUriHandler.cxx
@@ -278,7 +278,7 @@ public:
 
     osgViewer::GraphicsWindow* window = NULL;
 
-    if (false == windowName.empty()) {
+    if (!windowName.empty()) {
       for (osgViewer::ViewerBase::Windows::iterator itr = windows.begin(); itr != windows.end(); ++itr) {
         if ((*itr)->getTraits()->windowName == windowName) {
           window = *itr;
@@ -288,7 +288,7 @@ public:
     }
 
     if ( NULL == window) {
-      if (false == windowName.empty()) {
+      if (!windowName.empty()) {
         SG_LOG(SG_NETWORK, SG_INFO, "requested window " << windowName << " not found, using first window");
       }
       window = *windows.begin();
@@ -462,7 +462,7 @@ bool ScreenshotUriHandler::handleGetRequest(const HTTPRequest & request, HTTPRes
   //  string camera = request.RequestVariables.get("camera");
   string window = request.RequestVariables.get("window");
 
-  bool stream = (false == request.RequestVariables.get("stream").empty());
+  bool stream = (!request.RequestVariables.get("stream").empty());
 
   int canvasindex = -1;
   string s_canvasindex = request.RequestVariables.get("canvasindex");
@@ -494,7 +494,7 @@ bool ScreenshotUriHandler::handleGetRequest(const HTTPRequest & request, HTTPRes
     return true;
   }
 
-  if (false == stream) {
+  if (!stream) {
     response.Header["Content-Type"] = string("image/").append(type);
     response.Header["Content-Disposition"] = string("inline; filename=\"fgfs-screen.").append(type).append("\"");
   } else {
diff --git a/src/Network/http/httpd.cxx b/src/Network/http/httpd.cxx
index 07a73a6da..05d9511c1 100644
--- a/src/Network/http/httpd.cxx
+++ b/src/Network/http/httpd.cxx
@@ -322,7 +322,7 @@ int RegularConnection::request(struct mg_connection * connection)
 
   // find a handler for the uri and remember it for possible polls on this connection
   _handler = _httpd->findHandler(request.Uri);
-  if (false == _handler.valid()) {
+  if (!_handler.valid()) {
     // uri not registered - pass false to indicate we have not processed the request
     return MG_FALSE;
   }
@@ -350,7 +350,7 @@ int RegularConnection::request(struct mg_connection * connection)
     if (name.empty() || value.empty()) continue;
     mg_send_header(connection, name.c_str(), value.c_str());
   }
-  if (done || false == response.Content.empty()) {
+  if (done || !response.Content.empty()) {
     SG_LOG(SG_NETWORK, SG_INFO,
         "RegularConnection::request() responding " << response.Content.length() << " Bytes, done=" << done);
     mg_send_data(connection, response.Content.c_str(), response.Content.length());
@@ -361,7 +361,7 @@ int RegularConnection::request(struct mg_connection * connection)
 int RegularConnection::poll(struct mg_connection * connection)
 {
   setConnection(connection);
-  if (false == _handler.valid()) return MG_FALSE;
+  if (!_handler.valid()) return MG_FALSE;
   // only return MG_TRUE if we handle this request
   return _handler->poll(this) ? MG_TRUE : MG_MORE;
 }
@@ -508,7 +508,7 @@ void MongooseHttpd::init()
         }
         string & lhs = rw_entries[0];
         string & rhs = rw_entries[1];
-        if (false == rewrites.empty()) rewrites.append(1, ',');
+        if (!rewrites.empty()) rewrites.append(1, ',');
         rewrites.append(lhs).append(1, '=');
         SGPath targetPath(rhs);
         if (targetPath.isAbsolute() ) {
@@ -518,7 +518,7 @@ void MongooseHttpd::init()
           rewrites.append(fgRoot).append(1, '/').append(rhs);
         }
       }
-      if (false == rewrites.empty()) mg_set_option(_server, "url_rewrites", rewrites.c_str());
+      if (!rewrites.empty()) mg_set_option(_server, "url_rewrites", rewrites.c_str());
     }
     mg_set_option(_server, "enable_directory_listing", n->getStringValue("enable-directory-listing", "yes"));
     mg_set_option(_server, "idle_timeout_ms", n->getStringValue("idle-timeout-ms", "30000"));
@@ -638,7 +638,7 @@ int MongooseHttpd::staticRequestHandler(struct mg_connection * connection, mg_ev
 FGHttpd * FGHttpd::createInstance(SGPropertyNode_ptr configNode)
 {
 // only create a server if a port has been configured
-  if (false == configNode.valid()) return NULL;
+  if (!configNode.valid()) return NULL;
   string port = configNode->getStringValue("options/listening-port", "");
   if (port.empty()) return NULL;
   return new MongooseHttpd(configNode);
diff --git a/src/Network/http/jsonprops.cxx b/src/Network/http/jsonprops.cxx
index 140d6c84b..e1e3fa4a4 100644
--- a/src/Network/http/jsonprops.cxx
+++ b/src/Network/http/jsonprops.cxx
@@ -145,7 +145,7 @@ void JSON::toProp(cJSON * json, SGPropertyNode_ptr base)
 
     //TODO: better check for valid name
     string namestr = simgear::strutils::strip(string(name));
-    if( false == namestr.empty() ) {
+    if( !namestr.empty() ) {
       int index = 0;
       cj = cJSON_GetObjectItem(json, "index");
       if (NULL != cj) index = cj->valueint;
diff --git a/src/Sound/flitevoice.cxx b/src/Sound/flitevoice.cxx
index ce39fa2f6..97662935a 100644
--- a/src/Sound/flitevoice.cxx
+++ b/src/Sound/flitevoice.cxx
@@ -63,7 +63,7 @@ void FGFLITEVoice::speak(const string & msg)
 {
   // this is called from voice.cxx:FGVoiceMgr::FGVoiceThread::run
   string s = simgear::strutils::strip(msg);
-  if (false == s.empty()) {
+  if (!s.empty()) {
     _sampleQueue.push(_synthesizer->synthesize(msg, 1.0, 0.5, 0.5));
   }
 }