Use !std::string::empty() for string-is-not-empty comparisons

src/arrow.cpp

@@ -266,12 +266,12 @@ void arrow::update_symbols()
 		}
 
 		image_filename = dirname + style_ + "/" + prefix;
-		if (suffix != "")
+		if (!suffix.empty())
 		{
 			image_filename += ("-" + suffix);
 		}
 		image_filename += ".png";
-		assert(image_filename != "");
+		assert(!image_filename.empty());
 
 		image::locator image = image::locator(image_filename, mods);
 		if (!image.file_exists())

src/display.cpp

@@ -1624,7 +1624,7 @@ void display::set_diagnostic(const std::string& msg)
 		diagnostic_label_ = 0;
 	}
 
-	if(msg != "") {
+	if(!msg.empty()) {
 		font::floating_label flabel(msg);
 		flabel.set_font_size(font::SIZE_PLUS);
 		flabel.set_color(font::YELLOW_COLOR);

src/floating_textbox.cpp

@@ -113,7 +113,7 @@ namespace gui{
 		label_string_ = label;
 		mode_ = mode;
 
-		if(check_label != "") {
+		if(!check_label.empty()) {
 			check_.reset(new gui::button(gui.video(),check_label,gui::button::TYPE_CHECK));
 			check_->set_check(checked);
 		}

src/game_initialization/create_engine.cpp

@@ -392,7 +392,7 @@ void create_engine::prepare_for_campaign(const std::string& difficulty)
 {
 	DBG_MP << "preparing data for campaign by reloading game config\n";
 
-	if(difficulty != "") {
+	if(!difficulty.empty()) {
 		state_.classification().difficulty = difficulty;
 	} else if(!selected_campaign_difficulty_.empty()) {
 		state_.classification().difficulty = selected_campaign_difficulty_;

src/game_launcher.cpp

@@ -850,7 +850,7 @@ bool game_launcher::play_multiplayer(mp_selection res)
 	} catch (mapgen_exception& e) {
 		gui2::show_error_message(video(), _("Map generator error: ") + e.message);
 	} catch(wesnothd_error& e) {
-		if(e.message != "") {
+		if(!e.message.empty()) {
 			ERR_NET << "caught network error: " << e.message << std::endl;
 			gui2::show_transient_message(video()
 					, ""
@@ -859,7 +859,7 @@ bool game_launcher::play_multiplayer(mp_selection res)
 			ERR_NET << "caught network error" << std::endl;
 		}
 	} catch(config::error& e) {
-		if(e.message != "") {
+		if(!e.message.empty()) {
 			ERR_CONFIG << "caught config::error: " << e.message << std::endl;
 			gui2::show_transient_message(video(), "", e.message);
 		} else {

src/generators/cave_map_generator.cpp

@@ -308,7 +308,7 @@ double passage_path_calculator::cost(const map_location& loc, const double) cons
 void cave_map_generator::cave_map_generator_job::place_passage(const passage& p)
 {
 	const std::string& chance = p.cfg["chance"];
-	if(chance != "" && int(rng_()%100) < std::stoi(chance)) {
+	if(!chance.empty() && int(rng_()%100) < std::stoi(chance)) {
 		return;
 	}
 

src/generators/default_map_generator_job.cpp

@@ -168,7 +168,7 @@ namespace {
 		to(t_translation::GRASS_LAND)
 	{
 		const std::string& terrain = cfg["terrain"];
-		if(terrain != "") {
+		if(!terrain.empty()) {
 			to = t_translation::read_terrain_code(terrain);
 		}
 	}
@@ -207,7 +207,7 @@ namespace {
 		, to(t_translation::NONE_TERRAIN)
 	{
 		const std::string& to_str = cfg["to"];
-		if(to_str != "") {
+		if(!to_str.empty()) {
 			to = t_translation::read_terrain_code(to_str);
 		}
 	}
@@ -1116,7 +1116,7 @@ std::string default_map_generator_job::default_generate_map(generator_data data,
 				terrain[x][y] = letter;
 				if(misc_labels != nullptr) {
 					const map_location loc(x - data.width / 3, y - data.height / 3); //add to use for village naming
-					if(road_base_name != "")
+					if(!road_base_name.empty())
 						road_names.emplace(loc, road_base_name);
 				}
 			}

src/gui/dialogs/campaign_selection.cpp

@@ -95,7 +95,7 @@ void campaign_selection::campaign_selected(window& window)
 	}
 
 	assert(tree.selected_item());
-	if(tree.selected_item()->id() != "") {
+	if(!tree.selected_item()->id().empty()) {
 		auto iter = std::find(page_ids_.begin(), page_ids_.end(), tree.selected_item()->id());
 		const int choice = iter - page_ids_.begin();
 		if(iter == page_ids_.end()) {
@@ -296,7 +296,7 @@ void campaign_selection::post_show(window& window)
 	}
 
 	assert(tree.selected_item());
-	if(tree.selected_item()->id() != "") {
+	if(!tree.selected_item()->id().empty()) {
 		auto iter = std::find(page_ids_.begin(), page_ids_.end(), tree.selected_item()->id());
 		if(iter != page_ids_.end()) {
 			choice_ = iter - page_ids_.begin();

src/help/help.cpp

@@ -206,7 +206,7 @@ void show_help(CVideo& video, const section &toplevel_sec,
 		hb.set_location(xloc + left_padding, yloc + top_padding);
 		hb.set_width(width - left_padding - right_padding);
 		hb.set_height(height - top_padding - bot_padding);
-		if (show_topic != "") {
+		if (!show_topic.empty()) {
 			hb.show_topic(show_topic);
 		}
 		else {

src/help/help_browser.cpp

@@ -145,7 +145,7 @@ void help_browser::handle_event(const SDL_Event &event)
 			const int mousex = mouse_event.x;
 			const int mousey = mouse_event.y;
 			const std::string ref = text_area_.ref_at(mousex, mousey);
-			if (ref != "") {
+			if (!ref.empty()) {
 				const topic *t = find_topic(toplevel_, ref);
 				if (t == nullptr) {
 					std::stringstream msg;
@@ -170,7 +170,7 @@ void help_browser::update_cursor()
 	int mousex, mousey;
 	SDL_GetMouseState(&mousex,&mousey);
 	const std::string ref = text_area_.ref_at(mousex, mousey);
-	if (ref != "" && !ref_cursor_) {
+	if (!ref.empty() && !ref_cursor_) {
 		cursor::set(cursor::HYPERLINK);
 		ref_cursor_ = true;
 	}

src/help/help_impl.cpp

@@ -1245,7 +1245,7 @@ std::vector<std::string> parse_text(const std::string &text)
 		msg << "Element '" << ss.str() << "' continues through end of string.";
 		throw parse_error(msg.str());
 	}
-	if (ss.str() != "") {
+	if (!ss.str().empty()) {
 		// Add the last string.
 		res.push_back(ss.str());
 	}
@@ -1289,7 +1289,7 @@ std::string convert_to_wml(const std::string &element_name, const std::string &c
 		msg << "Unterminated single quote after: '" << ss.str() << "'";
 		throw parse_error(msg.str());
 	}
-	if (ss.str() != "") {
+	if (!ss.str().empty()) {
 		attributes.push_back(ss.str());
 	}
 	ss.str("");
@@ -1407,7 +1407,7 @@ void generate_contents()
 					// toplevel. Hence, add it to the hidden ones if it
 					// is not referenced from another section.
 					if (!section_is_referenced(id, *help_config)) {
-						if (ss.str() != "") {
+						if (!ss.str().empty()) {
 							ss << ",";
 						}
 						ss << id;
@@ -1421,7 +1421,7 @@ void generate_contents()
 				const std::string id = topic["id"];
 				if (find_topic(default_toplevel, id) == nullptr) {
 					if (!topic_is_referenced(id, *help_config)) {
-						if (ss.str() != "") {
+						if (!ss.str().empty()) {
 							ss << ",";
 						}
 						ss << id;

src/help/help_text_area.cpp

@@ -116,7 +116,7 @@ void help_text_area::set_items()
 	std::vector<std::string> const &parsed_items = shown_topic_->text.parsed_text();
 	std::vector<std::string>::const_iterator it;
 	for (it = parsed_items.begin(); it != parsed_items.end(); ++it) {
-		if (*it != "" && (*it)[0] == '[') {
+		if (!(*it).empty() && (*it)[0] == '[') {
 			// Should be parsed as WML.
 			try {
 				config cfg;
@@ -247,7 +247,7 @@ void help_text_area::handle_jump_cfg(const config &cfg)
 		throw parse_error("Jump markup must have either a to or an amount attribute.");
 	}
 	unsigned jump_to = curr_loc_.first;
-	if (amount_str != "") {
+	if (!amount_str.empty()) {
 		unsigned amount;
 		try {
 			amount = lexical_cast<unsigned, std::string>(amount_str);
@@ -257,7 +257,7 @@ void help_text_area::handle_jump_cfg(const config &cfg)
 		}
 		jump_to += amount;
 	}
-	if (to_str != "") {
+	if (!to_str.empty()) {
 		unsigned to;
 		try {
 			to = lexical_cast<unsigned, std::string>(to_str);
@@ -577,7 +577,7 @@ std::string help_text_area::ref_at(const int x, const int y)
 		const std::list<item>::const_iterator it =
 			std::find_if(items_.begin(), items_.end(), item_at(local_x, cmp_y));
 		if (it != items_.end()) {
-			if ((*it).ref_to != "") {
+			if (!(*it).ref_to.empty()) {
 				return ((*it).ref_to);
 			}
 		}

src/hotkey/hotkey_item.hpp

@@ -264,7 +264,7 @@ class hotkey_keyboard: public hotkey_base
 	 */
 	virtual bool valid() const
 	{
-		return keycode_ != SDLK_UNKNOWN && text_ != "";
+		return keycode_ != SDLK_UNKNOWN && !text_.empty();
 	}
 
 protected:

src/map/label.cpp

@@ -118,7 +118,7 @@ const terrain_label* map_labels::get_label(const map_location& loc) const
 
 	// No such team label. Try to find global label, except if that's what we just did.
 	// NOTE: This also avoid infinite recursion
-	if(res == nullptr && team_name() != "") {
+	if(res == nullptr && !team_name().empty()) {
 		return get_label(loc, "");
 	}
 

src/playsingle_controller.cpp

@@ -155,7 +155,7 @@ void playsingle_controller::play_scenario_init()
 		saved_game_.replay_start() = to_config();
 	}
 	start_game();
-	if( saved_game_.classification().random_mode != "" && is_networked_mp()) {
+	if(!saved_game_.classification().random_mode.empty() && is_networked_mp()) {
 		// This won't cause errors later but we should notify the user about it in case he didn't knew it.
 		gui2::show_transient_message(
 			gui_->video(),

src/saved_game.cpp

@@ -309,9 +309,9 @@ void saved_game::expand_mp_events()
 		boost::copy( mp_settings_.active_mods
 			| boost::adaptors::transformed(modevents_entry_for("modification"))
 			, std::back_inserter(mods) );
-		if(mp_settings_.mp_era != "") //We don't want the error message below if there is no era (= if this is a sp game)
+		if(!mp_settings_.mp_era.empty()) //We don't want the error message below if there is no era (= if this is a sp game)
 		{ mods.emplace_back("era", mp_settings_.mp_era); }
-		if(classification_.campaign != "")
+		if(!classification_.campaign.empty())
 		{ mods.emplace_back("campaign", classification_.campaign); }
 
 		// In the first iteration mod contains no [resource]s in all other iterations, mods contains only [resource]s

src/serialization/string_utils.cpp

@@ -597,7 +597,7 @@ std::string si_string(double input, bool base2, const std::string& unit) {
 	si_string_impl_stream_write(ss, input);
 	ss << ' '
 	   << *prefix
-	   << (base2 && (*prefix != "") ? _("infix_binary^i") : "")
+	   << (base2 && (!(*prefix).empty()) ? _("infix_binary^i") : "")
 	   << unit;
 	return ss.str();
 }

src/server/game.cpp

@@ -915,7 +915,7 @@ bool game::process_turn(simple_wml::document& data, const socket_ptr user) {
 			marked.push_back(index - marked.size());
 		} else if ((**command).child("speak")) {
 			simple_wml::node& speak = *(**command).child("speak");
-			if (speak["to_sides"] != "" || is_muted_observer(user)) {
+			if (!speak["to_sides"].empty() || is_muted_observer(user)) {
 				DBG_GAME << "repackaging..." << std::endl;
 				repackage = true;
 			}

src/server/server.cpp

@@ -814,7 +814,7 @@ void server::add_player(socket_ptr socket, const wesnothd::player& player)
 
 	send_to_player(socket, games_and_users_list_);
 
-	if (motd_ != "") {
+	if (!motd_.empty()) {
 		send_server_message(socket, motd_);
 	}
 
@@ -2599,7 +2599,7 @@ void server::motd_handler(const std::string& /*issuer_name*/, const std::string&
 	assert(out != NULL);
 
 	if (parameters == "") {
-		if (motd_ != "") {
+		if (!motd_.empty()) {
 			*out << "Message of the day:\n" << motd_;
 			return;
 		} else {

src/tests/test_config.cpp

@@ -151,11 +151,11 @@ BOOST_AUTO_TEST_CASE ( test_config_attribute_value )
 
 		// blank != "" test.
 	c = config();
-	BOOST_CHECK(cc["x"] != "");
+	BOOST_CHECK(!cc["x"].empty());
 	BOOST_CHECK(cc["x"].empty());
 	BOOST_CHECK(cc["x"].blank());
 
-	BOOST_CHECK(c["x"] != "");
+	BOOST_CHECK(!c["x"].empty());
 	BOOST_CHECK(c["x"].empty());
 	BOOST_CHECK(c["x"].blank());
 

src/units/animation.cpp

@@ -89,23 +89,23 @@ struct animation_cursor
 			const std::string s_branch_value     = branch.attributes["value"];
 			const std::string s_branch_value_2nd = branch.attributes["value_second"];
 
-			if(s_branch_hits != "" && s_branch_hits == s_cfg_hits) {
+			if(!s_branch_hits.empty() && s_branch_hits == s_cfg_hits) {
 				previously_hits_set = true;
 			}
 
-			if(s_branch_direction != "" && s_branch_direction == s_cfg_direction) {
+			if(!s_branch_direction.empty() && s_branch_direction == s_cfg_direction) {
 				previously_direction_set = true;
 			}
 
-			if(s_branch_terrain != "" && s_branch_terrain == s_cfg_terrain) {
+			if(!s_branch_terrain.empty() && s_branch_terrain == s_cfg_terrain) {
 				previously_terrain_set = true;
 			}
 
-			if(s_branch_value != "" && s_branch_value == s_cfg_value) {
+			if(!s_branch_value.empty() && s_branch_value == s_cfg_value) {
 				previously_value_set = true;
 			}
 
-			if(s_branch_value_2nd != "" && s_branch_value_2nd == s_cfg_value_2nd) {
+			if(!s_branch_value_2nd.empty() && s_branch_value_2nd == s_cfg_value_2nd) {
 				previously_value_2nd_set = true;
 			}
 		}

src/units/attack_type.cpp

@@ -65,7 +65,7 @@ attack_type::attack_type(const config& cfg) :
 		description_ = translation::egettext(id_.c_str());
 
 	if(icon_.empty()){
-		if (id_ != "")
+		if (!id_.empty())
 			icon_ = "attacks/" + id_ + ".png";
 		else
 			icon_ = "attacks/blank-attack.png";

src/units/types.cpp

@@ -391,7 +391,7 @@ void unit_type::build_created(
 	}
 
 	const std::string& advances_to_val = cfg_["advances_to"];
-	if(advances_to_val != "null" && advances_to_val != "") {
+	if(advances_to_val != "null" && !advances_to_val.empty()) {
 		advances_to_ = utils::split(advances_to_val);
 	}
 

src/units/unit.cpp

@@ -515,7 +515,7 @@ unit::unit(const config& cfg, bool use_traits, const vconfig* vcfg)
 	std::vector<std::string> temp_advances = utils::split(cfg["advances_to"]);
 	if(temp_advances.size() == 1 && temp_advances.front() == "null") {
 		advances_to_.clear();
-	} else if(temp_advances.size() >= 1 && temp_advances.front() != "") {
+	} else if(temp_advances.size() >= 1 && !temp_advances.front().empty()) {
 		advances_to_ = temp_advances;
 	}
 
@@ -1759,7 +1759,7 @@ std::string unit::describe_builtin_effect(std::string apply_to, const config& ef
 		std::string desc;
 		for(attack_ptr a : attacks_) {
 			bool affected = a->describe_modification(effect, &desc);
-			if(affected && desc != "") {
+			if(affected && !desc.empty()) {
 				attack_names.emplace_back(a->name(), "wesnoth-units");
 			}
 		}

src/widgets/widget.cpp

@@ -317,7 +317,7 @@ void widget::set_tooltip_string(const std::string& str)
 void widget::process_help_string(int mousex, int mousey)
 {
 	if (!hidden() && sdl::point_in_rect(mousex, mousey, rect_)) {
-		if(help_string_ == 0 && help_text_ != "") {
+		if(help_string_ == 0 && !help_text_.empty()) {
 			//std::cerr << "setting help string to '" << help_text_ << "'\n";
 			help_string_ = video().set_help_string(help_text_);
 		}