clang-tidy: modernize the code by using empty

alib2algo/src/automaton/generate/NumberModuloAutomaton.cpp

@@ -26,7 +26,7 @@ automaton::DFA < std::string, unsigned > NumberModuloAutomaton::generate ( unsig
 		base_map.push_back ( ext::to_string ( i ) );
 	for ( unsigned i = 10; i < base; ++ i )
-		base_map.push_back ( std::string ( 'A' + i, 1 ) );
+		base_map.emplace_back ( 'A' + i, 1 );
 	automaton::DFA < std::string, unsigned > res ( 0 );

alib2cli/src/readline/StringLineInterface.h

@@ -18,7 +18,7 @@ class StringLineInterface final : public cli::LineInterface {
 	std::string m_string;
 	bool readline ( std::string & line, bool ) override {
-		if ( m_string == "" )
+		if ( m_string.empty ( ) )
 			return false;
 		line = std::exchange ( m_string, "" );

tests/testing/TestFiles.cpp

@@ -41,7 +41,7 @@ std::string TestFiles::GetOne ( const std::regex& regex ) {
 	if ( res.size ( ) > 1 )
 		throw std::invalid_argument ( "Multiple files found for TestFiles::GetOne in '"s + std::string ( TEST_FILES_BASEDIR ) + "'"s );
-	if ( res.size ( ) == 0 )
+	if ( res.empty ( ) )
 		throw std::invalid_argument ( "No files found for TestFiles::GetOne. TestFilesDir is "s + std::string ( TEST_FILES_BASEDIR ) + "'"s );
 	return res.at ( 0 );