"Performance" fixes suggested by cppcheck

While cppcheck did not turn out any suspicious error messages, using
the "performance" flag highlighted several nitpicks in three categories
 * do not use it++ for iterators, ++it is better
 * do not use size() to test for emptyness, empty() is here
 * do not use "const T" as a function parameter, "const & T" is better

I doubt that any of these is a real performance problem, but the code is cleaner anyway.

src/Author.cpp

@@ -85,7 +85,7 @@ int AuthorList::record(Author const & a)
 	// If we record an author which equals the current
 	// author, we copy the buffer_id, so that it will
 	// keep the same id in the file.
-	if (authors_.size() > 0 && a == authors_[0])
+	if (!authors_.empty() && a == authors_[0])
 		authors_[0].setBufferId(a.bufferId());
 
 	Authors::const_iterator it(authors_.begin());

src/Buffer.cpp

@@ -2879,7 +2879,7 @@ MacroData const * Buffer::Impl::getBufferMacro(docstring const & name,
 				// try previous macro if there is one
 				if (it == nameIt->second.begin())
 					break;
-				it--;
+				--it;
 			}
 		}
 	}

src/BufferParams.cpp

@@ -942,7 +942,7 @@ void BufferParams::writeFile(ostream & os) const
 		os << "\\begin_removed_modules" << '\n';
 		list<string>::const_iterator it = removed_modules_.begin();
 		list<string>::const_iterator en = removed_modules_.end();
-		for (; it != en; it++)
+		for (; it != en; ++it)
 			os << *it << '\n';
 		os << "\\end_removed_modules" << '\n';
 	}
@@ -952,7 +952,7 @@ void BufferParams::writeFile(ostream & os) const
 		os << "\\begin_modules" << '\n';
 		LayoutModuleList::const_iterator it = layout_modules_.begin();
 		LayoutModuleList::const_iterator en = layout_modules_.end();
-		for (; it != en; it++)
+		for (; it != en; ++it)
 			os << *it << '\n';
 		os << "\\end_modules" << '\n';
 	}
@@ -962,7 +962,7 @@ void BufferParams::writeFile(ostream & os) const
 		os << "\\begin_includeonly" << '\n';
 		list<string>::const_iterator it = included_children_.begin();
 		list<string>::const_iterator en = included_children_.end();
-		for (; it != en; it++)
+		for (; it != en; ++it)
 			os << *it << '\n';
 		os << "\\end_includeonly" << '\n';
 	}
@@ -2026,11 +2026,11 @@ void BufferParams::makeDocumentClass()
 
 	it = layout_modules_.begin();
 	en = layout_modules_.end();
-	for (; it != en; it++)
+	for (; it != en; ++it)
 		mods.push_back(*it);
 	it = cite_engine_.begin();
 	en = cite_engine_.end();
-	for (; it != en; it++)
+	for (; it != en; ++it)
 		mods.push_back(*it);
 	doc_class_ = &(DocumentClassBundle::get().makeDocumentClass(*baseClass(), mods));
 
@@ -2056,7 +2056,7 @@ bool BufferParams::addLayoutModule(string const & modName)
 {
 	LayoutModuleList::const_iterator it = layout_modules_.begin();
 	LayoutModuleList::const_iterator end = layout_modules_.end();
-	for (; it != end; it++)
+	for (; it != end; ++it)
 		if (*it == modName)
 			return false;
 	layout_modules_.push_back(modName);
@@ -2391,7 +2391,7 @@ void BufferParams::readRemovedModules(Lexer & lex)
 	// start of the read.
 	list<string>::const_iterator rit = removed_modules_.begin();
 	list<string>::const_iterator const ren = removed_modules_.end();
-	for (; rit != ren; rit++) {
+	for (; rit != ren; ++rit) {
 		LayoutModuleList::iterator const mit = layout_modules_.begin();
 		LayoutModuleList::iterator const men = layout_modules_.end();
 		LayoutModuleList::iterator found = find(mit, men, *rit);

src/CutAndPaste.cpp

@@ -528,7 +528,7 @@ void copySelectionHelper(Buffer const & buf, Text const & text,
 	ParagraphList::iterator it = copy_pars.begin();
 	ParagraphList::iterator it_end = copy_pars.end();
 
-	for (; it != it_end; it++) {
+	for (; it != it_end; ++it) {
 		// Since we have a copy of the paragraphs, the insets
 		// do not have a proper buffer reference. It makes
 		// sense to add them temporarily, because the
@@ -553,7 +553,7 @@ void copySelectionHelper(Buffer const & buf, Text const & text,
 	// do some final cleanup now, to make sure that the paragraphs
 	// are not linked to something else.
 	it = copy_pars.begin();
-	for (; it != it_end; it++) {
+	for (; it != it_end; ++it) {
 		it->setBuffer(*static_cast<Buffer *>(0));
 		it->setInsetOwner(0);
 	}

src/LayoutModuleList.cpp

@@ -59,7 +59,7 @@ bool LayoutModuleList::moduleCanBeAdded(string const & modName,
 	// Is the module already present?
 	const_iterator it = begin();
 	const_iterator const en = end();
-	for (; it != en; it++)
+	for (; it != en; ++it)
 		if (*it == modName) 
 			return false;
 
@@ -131,7 +131,7 @@ void LayoutModuleList::addDefaultModules(LayoutFile const * const lay,
 	iterator insertpos = begin();
 	int numinserts = 0;
 
-	for (; mit != men; mit++) {
+	for (; mit != men; ++mit) {
 		string const & modName = *mit;
 		// make sure the user hasn't removed it
 		if (find(removedModules.begin(), removedModules.end(), modName) !=

src/LyX.cpp

@@ -340,7 +340,7 @@ int LyX::exec(int & argc, char * argv[])
 			vector<string>::const_iterator bcit  = pimpl_->batch_commands.begin();
 			vector<string>::const_iterator bcend = pimpl_->batch_commands.end();
 			DispatchResult dr;
-			for (; bcit != bcend; bcit++) {
+			for (; bcit != bcend; ++bcit) {
 				LYXERR(Debug::ACTION, "Buffer::dispatch: cmd: " << *bcit);
 				buf->dispatch(*bcit, dr);
 				final_success |= !dr.error();
@@ -587,7 +587,7 @@ void LyX::execCommands()
 
 	vector<string>::const_iterator bcit  = pimpl_->batch_commands.begin();
 	vector<string>::const_iterator bcend = pimpl_->batch_commands.end();
-	for (; bcit != bcend; bcit++) {
+	for (; bcit != bcend; ++bcit) {
 		LYXERR(Debug::INIT, "About to handle -x '" << *bcit << '\'');
 		lyx::dispatch(lyxaction.lookupFunc(*bcit));
 	}

src/Paragraph.cpp

@@ -134,7 +134,7 @@ public:
 		current_change_number_ = 0;
 	}
 
-	void setRange(FontSpan const fp, SpellChecker::Result state)
+	void setRange(FontSpan const & fp, SpellChecker::Result state)
 	{
 		Ranges result;
 		RangesIterator et = ranges_.end();

src/Text.cpp

@@ -1696,7 +1696,7 @@ bool Text::dissolveInset(Cursor & cur)
 		// change it to the buffer language.
 		ParagraphList::iterator it = plist.begin();
 		ParagraphList::iterator it_end = plist.end();
-		for (; it != it_end; it++)
+		for (; it != it_end; ++it)
 			it->changeLanguage(b.params(), latex_language, b.language());
 
 		pasteParagraphList(cur, plist, b.params().documentClassPtr(),

src/TextClass.cpp

@@ -1465,7 +1465,7 @@ DocumentClass & DocumentClassBundle::makeDocumentClass(
 	DocumentClass & doc_class = newClass(baseClass);
 	LayoutModuleList::const_iterator it = modlist.begin();
 	LayoutModuleList::const_iterator en = modlist.end();
-	for (; it != en; it++) {
+	for (; it != en; ++it) {
 		string const modName = *it;
 		LyXModule * lm = theModuleList[modName];
 		if (!lm) {

src/TextMetrics.cpp

@@ -1389,7 +1389,8 @@ pit_type TextMetrics::getPitNearY(int y)
 	int yy = -1;
 	ParMetricsCache::const_iterator it = par_metrics_.begin();
 	ParMetricsCache::const_iterator et = par_metrics_.end();
-	ParMetricsCache::const_iterator last = et; last--;
+	ParMetricsCache::const_iterator last = et;
+	--last;
 
 	ParagraphMetrics const & pm = it->second;
 

src/frontends/qt4/GuiDocument.cpp

@@ -2132,7 +2132,7 @@ namespace {
 	docstring formatStrVec(vector<string> const & v, docstring const & s)
 	{
 		//this mess formats the list as "v[0], v[1], ..., [s] v[n]"
-		if (v.size() == 0)
+		if (v.empty())
 			return docstring();
 		if (v.size() == 1)
 			return translateIfPossible(from_utf8(v[0]));
@@ -2188,11 +2188,11 @@ void GuiDocument::modulesToParams(BufferParams & bp)
 	list<string>::const_iterator ren = reqmods.end();
 
 	// check each of the default modules
-	for (; rit != ren; rit++) {
+	for (; rit != ren; ++rit) {
 		list<string>::const_iterator mit = bp.getModules().begin();
 		list<string>::const_iterator men = bp.getModules().end();
 		bool found = false;
-		for (; mit != men; mit++) {
+		for (; mit != men; ++mit) {
 			if (*rit == *mit) {
 				found = true;
 				break;

src/frontends/qt4/GuiGraphics.cpp

@@ -575,7 +575,7 @@ void GuiGraphics::paramsToDialog(InsetGraphicsParams const & igp)
 	set<string>::const_iterator end = grp.end();
 	groupCO->blockSignals(true);
 	groupCO->clear();
-	for (; it != end; it++)
+	for (; it != end; ++it)
 		groupCO->addItem(toqstr(*it), toqstr(*it));
 	groupCO->insertItem(0, qt_("None"), QString());
 	if (igp.groupId.empty())

src/frontends/qt4/LengthCombo.cpp

@@ -58,7 +58,7 @@ void LengthCombo::setCurrentItem(lyx::Length::UNIT unit)
 }
 
 
-void LengthCombo::setCurrentItem(QString const item)
+void LengthCombo::setCurrentItem(QString const & item)
 {
 	int num = QComboBox::count();
 	for (int i = 0; i < num; i++) {

src/frontends/qt4/LengthCombo.h

@@ -31,7 +31,7 @@ public:
 	/// set the current item from unit
 	virtual void setCurrentItem(lyx::Length::UNIT unit);
 	/// set the current item from length string
-	virtual void setCurrentItem(QString const item);
+	virtual void setCurrentItem(QString const & item);
 	/// set the current item from int
 	virtual void setCurrentItem(int item);
 	/// get the current item

src/frontends/qt4/Menus.cpp

@@ -747,7 +747,7 @@ void MenuDefinition::expandGraphicsGroups(BufferView const * bv)
 	set<string>::const_iterator end = grp.end();
 	add(MenuItem(MenuItem::Command, qt_("No Group"),
 		     FuncRequest(LFUN_SET_GRAPHICS_GROUP)));
-	for (; it != end; it++) {
+	for (; it != end; ++it) {
 		addWithStatusCheck(MenuItem(MenuItem::Command, toqstr(*it) + '|',
 				FuncRequest(LFUN_SET_GRAPHICS_GROUP, *it)));
 	}

src/frontends/qt4/Validator.cpp

@@ -97,7 +97,7 @@ LengthValidator * unsignedGlueLengthValidator(QLineEdit * ed)
 }
 
 
-LengthAutoValidator::LengthAutoValidator(QWidget * parent, QString const autotext)
+LengthAutoValidator::LengthAutoValidator(QWidget * parent, QString const & autotext)
 	: LengthValidator(parent),
 	  autotext_(autotext)
 {}
@@ -111,7 +111,7 @@ QValidator::State LengthAutoValidator::validate(QString & qtext, int & dummy) co
 }
 
 
-LengthAutoValidator * unsignedLengthAutoValidator(QLineEdit * ed, QString const autotext)
+LengthAutoValidator * unsignedLengthAutoValidator(QLineEdit * ed, QString const & autotext)
 {
 	LengthAutoValidator * v = new LengthAutoValidator(ed, autotext);
 	v->setBottom(Length());
@@ -119,7 +119,7 @@ LengthAutoValidator * unsignedLengthAutoValidator(QLineEdit * ed, QString const
 }
 
 
-DoubleAutoValidator::DoubleAutoValidator(QWidget * parent, QString const autotext)
+DoubleAutoValidator::DoubleAutoValidator(QWidget * parent, QString const & autotext)
 	: QDoubleValidator(parent),
 	  autotext_(autotext)
 {}

src/frontends/qt4/Validator.h

@@ -90,7 +90,7 @@ class LengthAutoValidator : public LengthValidator
 	Q_OBJECT
 public:
 	/// Define a validator for widget @c parent.
-	LengthAutoValidator(QWidget * parent, QString const autotext);
+	LengthAutoValidator(QWidget * parent, QString const & autotext);
 
 	/** @returns QValidator::Acceptable if @c data is a GlueLength
 		* or is "auto". If not, returns QValidator::Intermediate.
@@ -102,7 +102,7 @@ private:
 };
 
 /// @returns a new @c LengthAutoValidator that does not accept negative lengths.
-LengthAutoValidator * unsignedLengthAutoValidator(QLineEdit *, QString const autotext);
+LengthAutoValidator * unsignedLengthAutoValidator(QLineEdit *, QString const & autotext);
 
 
 /**
@@ -114,7 +114,7 @@ class DoubleAutoValidator : public QDoubleValidator
 {
 	Q_OBJECT
 public:
-	DoubleAutoValidator(QWidget * parent, QString const autotext);
+	DoubleAutoValidator(QWidget * parent, QString const & autotext);
 	DoubleAutoValidator(double bottom, double top, int decimals,
 		QObject * parent);
 	QValidator::State validate(QString & input, int & pos) const;

src/graphics/GraphicsLoader.cpp

@@ -96,7 +96,7 @@ void LoaderQueue::loadNext()
 		if (ptr->status() == WaitingToLoad)
 			ptr->startLoading();
 	}
-	if (cache_queue_.size()) {
+	if (!cache_queue_.empty()) {
 		startLoader();
 	} else {
 		stopLoader();

src/mathed/InsetMathArray.cpp

@@ -51,7 +51,7 @@ InsetMathArray::InsetMathArray(Buffer * buf, docstring const & name,
 		istringstream ls(line);
 		typedef istream_iterator<string> iter;
 		vector<string> v = vector<string>(iter(ls), iter());
-		if (v.size())
+		if (!v.empty())
 			dat.push_back(v);
 	}
 

src/mathed/InsetMathNest.cpp

@@ -2064,7 +2064,7 @@ MathCompletionList::MathCompletionList(Cursor const & cur)
 	}
 	sort(locals.begin(), locals.end());
 
-	if (globals.size() > 0)
+	if (!globals.empty())
 		return;
 
 	// fill in global macros

src/output_latex.cpp

@@ -239,7 +239,6 @@ void TeXEnvironment(Buffer const & buf, Text const & text,
 	// This is for debugging purpose at the end.
 	pit_type const par_begin = pit;
 	for (; pit < runparams.par_end; ++pit) {
-	
 		ParagraphList::const_iterator par = paragraphs.constIterator(pit);
 
 		// check first if this is an higher depth paragraph.
@@ -276,7 +275,6 @@ void TeXEnvironment(Buffer const & buf, Text const & text,
 			// be two for Standard paragraphs that are depth-increment'ed to be
 			// output correctly. However, tables can also be paragraphs so
 			// don't adjust them.
-			// 
 
 			// FIXME (Lgb): Will it ever harm to have one '\n' too
 			// many? i.e. that we sometimes will have
@@ -333,7 +331,7 @@ void latexArgInsets(Paragraph const & par, otexstream & os,
 		}
 	}
 
-	if (!reqargs && ilist.size() == 0)
+	if (!reqargs && ilist.empty())
 		return;
 
 	bool const have_optional_args = ilist.size() > reqargs;

src/output_xhtml.cpp

@@ -727,7 +727,7 @@ ParagraphList::const_iterator makeParagraphs(Buffer const & buf,
 		//   (ii) We didn't open it and html_in_par is true, 
 		//        but we are in the first par, and there is a next par.
 		ParagraphList::const_iterator nextpar = par;
-		nextpar++;
+		++nextpar;
 		bool const needclose = 
 			(opened && (!runparams.html_in_par || nextpar != pend))
 			|| (!opened && runparams.html_in_par && par == pbegin && nextpar != pend);

src/tex2lyx/Preamble.cpp

@@ -340,7 +340,7 @@ Author const & Preamble::getAuthor(std::string const & name) const
 {
 	Author author(from_utf8(name), empty_docstring());
 	for (AuthorList::Authors::const_iterator it = authors_.begin();
-	     it != authors_.end(); it++)
+	     it != authors_.end(); ++it)
 		if (*it == author)
 			return *it;
 	static Author const dummy;
@@ -887,7 +887,7 @@ bool Preamble::writeLyXHeader(ostream & os, bool subdoc)
 		os << "\\begin_modules\n";
 		vector<string>::const_iterator const end = used_modules.end();
 		vector<string>::const_iterator it = used_modules.begin();
-		for (; it != end; it++)
+		for (; it != end; ++it)
 			os << *it << '\n';
 		os << "\\end_modules\n";
 	}
@@ -936,7 +936,7 @@ bool Preamble::writeLyXHeader(ostream & os, bool subdoc)
 	os << "\\papersize " << h_papersize << "\n"
 	   << "\\use_geometry " << h_use_geometry << '\n';
 	for (map<string, string>::const_iterator it = h_use_packages.begin();
-	     it != h_use_packages.end(); it++)
+	     it != h_use_packages.end(); ++it)
 		os << "\\use_package " << it->first << ' ' << it->second << '\n';
 	os << "\\cite_engine " << h_cite_engine << '\n'
 	   << "\\cite_engine_type " << h_cite_engine_type << '\n'

src/tex2lyx/tex2lyx.cpp

@@ -262,7 +262,7 @@ bool checkModule(string const & name, bool command)
 		DocumentClassBundle & bundle = DocumentClassBundle::get();
 		LyXModuleList::const_iterator const end = theModuleList.end();
 		LyXModuleList::const_iterator it = theModuleList.begin();
-		for (; it != end; it++) {
+		for (; it != end; ++it) {
 			string const module = it->getID();
 			LayoutModuleList m;
 			// FIXME this excludes all modules that depend on another one
@@ -282,7 +282,7 @@ bool checkModule(string const & name, bool command)
 	// needed since it is not unlikely that two different modules define a
 	// command with the same name.
 	ModuleMap::iterator const end = modules.end();
-	for (ModuleMap::iterator it = modules.begin(); it != end; it++) {
+	for (ModuleMap::iterator it = modules.begin(); it != end; ++it) {
 		string const module = it->first;
 		if (!used_modules.moduleCanBeAdded(module, &baseClass))
 			continue;
@@ -682,7 +682,7 @@ bool tex2lyx(idocstream & is, ostream & os, string encoding)
 	if (!used_modules.empty()) {
 		LayoutModuleList::const_iterator const end = used_modules.end();
 		LayoutModuleList::const_iterator it = used_modules.begin();
-		for (; it != end; it++)
+		for (; it != end; ++it)
 			preamble.addModule(*it);
 	}
 	if (!preamble.writeLyXHeader(os, !active_environments.empty())) {

src/tex2lyx/text.cpp

@@ -461,7 +461,7 @@ docstring convert_unicodesymbols(docstring s)
 		set<string> req;
 		docstring parsed = encodings.fromLaTeXCommand(s,
 				Encodings::TEXT_CMD, termination, rem, &req);
-		for (set<string>::const_iterator it = req.begin(); it != req.end(); it++)
+		for (set<string>::const_iterator it = req.begin(); it != req.end(); ++it)
 			preamble.registerAutomaticallyLoadedPackage(*it);
 		os << parsed;
 		s = rem;
@@ -1556,7 +1556,7 @@ void parse_environment(Parser & p, ostream & os, bool outer,
 		if (!preamble.titleLayoutFound())
 			preamble.titleLayoutFound(newlayout->intitle);
 		set<string> const & req = newlayout->requires();
-		for (set<string>::const_iterator it = req.begin(); it != req.end(); it++)
+		for (set<string>::const_iterator it = req.begin(); it != req.end(); ++it)
 			preamble.registerAutomaticallyLoadedPackage(*it);
 	}
 
@@ -2487,7 +2487,7 @@ void parse_text(Parser & p, ostream & os, unsigned flags, bool outer,
 						preamble.titleLayoutFound(newlayout->intitle);
 					set<string> const & req = newlayout->requires();
 					for (set<string>::const_iterator it = req.begin();
-					     it != req.end(); it++)
+					     it != req.end(); ++it)
 						preamble.registerAutomaticallyLoadedPackage(*it);
 				} else
 					handle_ert(os,
@@ -2508,7 +2508,7 @@ void parse_text(Parser & p, ostream & os, unsigned flags, bool outer,
 			if (!preamble.titleLayoutFound())
 				preamble.titleLayoutFound(newlayout->intitle);
 			set<string> const & req = newlayout->requires();
-			for (set<string>::const_iterator it = req.begin(); it != req.end(); it++)
+			for (set<string>::const_iterator it = req.begin(); it != req.end(); ++it)
 				preamble.registerAutomaticallyLoadedPackage(*it);
 		}
 
@@ -2521,7 +2521,7 @@ void parse_text(Parser & p, ostream & os, unsigned flags, bool outer,
 			if (!preamble.titleLayoutFound())
 				preamble.titleLayoutFound(newlayout->intitle);
 			set<string> const & req = newlayout->requires();
-			for (set<string>::const_iterator it = req.begin(); it != req.end(); it++)
+			for (set<string>::const_iterator it = req.begin(); it != req.end(); ++it)
 				preamble.registerAutomaticallyLoadedPackage(*it);
 		}
 
@@ -3521,7 +3521,7 @@ void parse_text(Parser & p, ostream & os, unsigned flags, bool outer,
 					     << ", result is " << to_utf8(s)
 					     << "+" << to_utf8(rem) << endl;
 				os << to_utf8(s);
-				for (set<string>::const_iterator it = req.begin(); it != req.end(); it++)
+				for (set<string>::const_iterator it = req.begin(); it != req.end(); ++it)
 					preamble.registerAutomaticallyLoadedPackage(*it);
 			} else
 				// we did not find a non-ert version
@@ -4128,7 +4128,7 @@ void parse_text(Parser & p, ostream & os, unsigned flags, bool outer,
 				os << to_utf8(s);
 				if (termination)
 					skip_spaces_braces(p);
-				for (set<string>::const_iterator it = req.begin(); it != req.end(); it++)
+				for (set<string>::const_iterator it = req.begin(); it != req.end(); ++it)
 					preamble.registerAutomaticallyLoadedPackage(*it);
 			}
 			//cerr << "#: " << t << " mode: " << mode << endl;