Const Correctness and Bug Fixes

CMakeLists.txt

@@ -5,6 +5,7 @@ project(dbc VERSION 0.5.0 DESCRIPTION "C++ DBC Parser")
 
 # -- PROJECT OPTIONS  -- #
 option(DBC_ENABLE_TESTS "Enable Unittests" ON)
+option(DBC_MODERN_CPP "Enable support for modern C++" OFF)
 option(DBC_TEST_LOCALE_INDEPENDENCE "Used to deterime if the libary is locale agnostic when it comes to converting floats. You need `de_DE.UTF-8` locale installed for this testing." OFF)
 option(DBC_GENERATE_DOCS "Use doxygen if installed to generated documentation files" OFF)
 option(DBC_GENERATE_SINGLE_HEADER "This will run the generator for the single header file version. Default is OFF since we make a static build. Requires cargo installed." OFF)
@@ -21,8 +22,13 @@ set(CPACK_RESOURCE_FILE_README ${CMAKE_CURRENT_SOURCE_DIR}/README.md)
 include(CPack)
 
 # specify the C++ standard
-set(CMAKE_CXX_STANDARD 11)
-set(CMAKE_CXX_STANDARD_REQUIRED True)
+if (DBC_ENABLE_TESTS OR DBC_MODERN_CPP)
+	set(CMAKE_CXX_STANDARD 17)
+	set(CMAKE_CXX_STANDARD_REQUIRED True)
+else()
+	set(CMAKE_CXX_STANDARD 11)
+	set(CMAKE_CXX_STANDARD_REQUIRED True)
+endif()
 
 find_package(FastFloat QUIET)
 if (NOT ${FastFloat_FOUND})

include/libdbc/dbc.hpp

@@ -8,6 +8,10 @@
 #include <string>
 #include <vector>
 
+#if __cplusplus >= 201703L
+	#include <filesystem>
+#endif // __cplusplus >= 201703L
+
 namespace Libdbc {
 
 class Parser {
@@ -27,18 +31,25 @@ class DbcParser : public Parser {
 	void parse_file(const std::string& file_name) override;
 	void parse_file(std::istream& stream) override;
 
-	std::string get_version() const;
-	std::vector<std::string> get_nodes() const;
-	std::vector<Libdbc::Message> get_messages() const;
+	const std::string& get_version() const;
+	const std::vector<std::string>& get_nodes() const;
+	const std::vector<Libdbc::Message>& get_messages() const;
+
+	Message::ParseSignalsStatus parse_message(uint32_t message_id, const std::vector<uint8_t>& data, std::vector<double>& out_values) const;
 
-	Message::ParseSignalsStatus parse_message(uint32_t message_id, const std::vector<uint8_t>& data, std::vector<double>& out_values);
+	const std::vector<std::string>& unused_lines() const;
 
-	std::vector<std::string> unused_lines() const;
+	#if __cplusplus >= 201703L
+	static void validate_dbc_file(const std::filesystem::path&);
+	#else
+	static void validate_dbc_file(const std::string&);
+	#endif // __cplusplus >= 201703L
+	static void validate_dbc_file(std::istream& stream);
 
 private:
-	std::string version;
-	std::vector<std::string> nodes;
-	std::vector<Libdbc::Message> messages;
+	std::string version{};
+	std::vector<std::string> nodes{};
+	std::vector<Libdbc::Message> messages{};
 
 	std::regex version_re;
 	std::regex bit_timing_re;
@@ -48,7 +59,7 @@ class DbcParser : public Parser {
 	std::regex value_re;
 	std::regex signal_re;
 
-	std::vector<std::string> missed_lines;
+	std::vector<std::string> missed_lines{};
 
 	void parse_dbc_header(std::istream& file_stream);
 	void parse_dbc_nodes(std::istream& file_stream);

include/libdbc/exceptions/error.hpp

@@ -22,10 +22,12 @@ class ValidityError : public Exception {
 
 class NonDbcFileFormatError : public ValidityError {
 public:
-	NonDbcFileFormatError(const std::string& path, const std::string& extension) {
-		error_msg = {"File is not of DBC format. Expected a .dbc extension. Cannot read this type of file (" + path + "). Found the extension (" + extension
-					 + ")."};
-	}
+	explicit NonDbcFileFormatError(const std::string& path, const std::string& extension):
+	error_msg("File is not of DBC format. Expected a .dbc extension. Cannot read this type of file ("
+				+ path + "). Found the extension (" + extension + ")."
+	) { }
+	explicit NonDbcFileFormatError(const std::string& error):
+	error_msg("File is not of DBC format. Cannot read this type of file (" + error + ").") { }
 
 	const char* what() const throw() override {
 		return error_msg.c_str();
@@ -35,32 +37,16 @@ class NonDbcFileFormatError : public ValidityError {
 	std::string error_msg;
 };
 
-class DbcFileIsMissingVersion : public ValidityError {
+class DbcFileIsMissingVersion : public NonDbcFileFormatError {
 public:
-	DbcFileIsMissingVersion(const std::string& line) {
-		error_msg = {"Invalid dbc file. Missing the required version header. Attempting to read line: (" + line + ")."};
-	}
-
-	const char* what() const throw() override {
-		return error_msg.c_str();
-	}
-
-private:
-	std::string error_msg;
+	explicit DbcFileIsMissingVersion(const std::string& line):
+		NonDbcFileFormatError("Invalid dbc file. Missing the required version header. Attempting to read line: (" + line + ").") { }
 };
 
-class DbcFileIsMissingBitTiming : public ValidityError {
+class DbcFileIsMissingBitTiming : public NonDbcFileFormatError {
 public:
-	DbcFileIsMissingBitTiming(const std::string& line) {
-		error_msg = {"Invalid dbc file. Missing required bit timing in the header. Attempting to read line: (" + line + ")."};
-	}
-
-	const char* what() const throw() override {
-		return error_msg.c_str();
-	}
-
-private:
-	std::string error_msg;
+	explicit DbcFileIsMissingBitTiming(const std::string& line):
+		NonDbcFileFormatError("Invalid dbc file. Missing required bit timing in the header. Attempting to read line: (" + line + ").") { }
 };
 
 } // libdbc

include/libdbc/message.hpp

@@ -19,12 +19,13 @@ struct Message {
 		ErrorBigEndian,
 		ErrorUnknownID,
 		ErrorInvalidConversion,
+		ErrorInvalidSignalSize,
 	};
 
 	ParseSignalsStatus parse_signals(const std::vector<uint8_t>& data, std::vector<double>& values) const;
 
 	void append_signal(const Signal& signal);
-	std::vector<Signal> get_signals() const;
+	const std::vector<Signal>& get_signals() const;
 	uint32_t id() const;
 	uint8_t size() const;
 	const std::string& name() const;
@@ -33,11 +34,11 @@ struct Message {
 	virtual bool operator==(const Message& rhs) const;
 
 private:
-	uint32_t m_id;
-	std::string m_name;
-	uint8_t m_size;
-	std::string m_node;
-	std::vector<Signal> m_signals;
+	uint32_t m_id{};
+	std::string m_name{};
+	uint8_t m_size{};
+	std::string m_node{};
+	std::vector<Signal> m_signals{};
 
 	friend std::ostream& operator<<(std::ostream& out, const Message& msg);
 };

include/libdbc/signal.hpp

@@ -30,7 +30,7 @@ struct Signal {
 
 	Signal() = delete;
 	virtual ~Signal() = default;
-	explicit Signal(std::string name,
+	explicit Signal(const std::string& name,
 					bool is_multiplexed,
 					uint32_t start_bit,
 					uint32_t size,
@@ -40,8 +40,8 @@ struct Signal {
 					double offset,
 					double min,
 					double max,
-					std::string unit,
-					std::vector<std::string> receivers);
+					const std::string& unit,
+					const std::vector<std::string>& receivers);
 
 	virtual bool operator==(const Signal& rhs) const;
 	bool operator<(const Signal& rhs) const;

include/libdbc/utils/utils.hpp

@@ -2,10 +2,21 @@
 #ifndef UTILS_HPP
 #define UTILS_HPP
 
+#include <algorithm>
 #include <iostream>
 #include <sstream>
 #include <string>
 
+#if __cplusplus >= 201703L
+#	include <string_view>
+#endif // __cplusplus >= 201703L
+
+#if __cpp_concepts >= 201907
+#include <concepts>
+template<typename Str>
+concept procsys_stringable = requires(Str s) { { s.data() + s.size() } -> std::convertible_to<const char*>; };
+#endif // __cpp_concepts >= 201907
+
 namespace Utils {
 
 class StreamHandler {
@@ -26,9 +37,103 @@ class StreamHandler {
 	static std::istream& skip_to_next_blank_line(std::istream& stream, std::string& line);
 };
 
+/**
+ * @brief Trims the specified characters from the beginning and end of the given string.
+ * 
+ * @tparam T The typeparam; must be stringable.
+ * @param value The string to trim.
+ * @return A new string with the specified characters trimmed.
+ * 
+ * @copyright 2025 Procyon Systems Inh. Simon Cahill (s.cahill@procyon-systems.de)
+ */
+#if __cplusplus >= 201703
+#	if __cpp_concepts >= 201907
+	template<procsys_stringable T>
+#	else
+	template<typename T>
+#	endif // __cpp_concepts >= 201907
+constexpr auto  trim(const T& value) {
+#else
+template<typename T>
+std::string		trim(const T& value) {
+#endif // #if __cplusplus >= 201703
+	T trimmedValue = value;
+	trimmedValue.erase(trimmedValue.begin(), std::find_if(trimmedValue.begin(), trimmedValue.end(), [](int ch) { return !std::isspace(ch); }));
+	trimmedValue.erase(std::find_if(trimmedValue.rbegin(), trimmedValue.rend(), [](int ch) { return !std::isspace(ch); }).base(), trimmedValue.end());
+	return trimmedValue;
+}
+
+/**
+ * @brief Trims the specified characters from the beginning and end of the given string.
+ * 
+ * @tparam T The typeparam; must be stringable.
+ * @param value The string to trim.
+ * @param trimChars The characters to trim from the string.
+ * @return A new string with the specified characters trimmed.
+ * 
+ * @copyright 2025 Procyon Systems Inh. Simon Cahill (s.cahill@procyon-systems.de)
+ */
+#if __cplusplus >= 201703
+#	if __cpp_concepts >= 201907
+	template<procsys_stringable T>
+#	else
+	template<typename T>
+#	endif // __cpp_concepts >= 201907
+constexpr auto  trim(const T& value, std::initializer_list<char>& trimChars) {
+#else
+template<typename T>
+std::string  	trim(const T& value, const std::initializer_list<char>& trimChars) {
+#endif // __cplusplus >= 201703
+	T trimmedValue = value;
+	trimmedValue.erase(trimmedValue.begin(), std::find_if(trimmedValue.begin(), trimmedValue.end(), [&trimChars](int ch) { return std::find(trimChars.begin(), trimChars.end(), static_cast<char>(ch)) == trimChars.end(); }));
+	trimmedValue.erase(std::find_if(trimmedValue.rbegin(), trimmedValue.rend(), [&trimChars](int ch) { return std::find(trimChars.begin(), trimChars.end(), static_cast<char>(ch)) == trimChars.end(); }).base(), trimmedValue.end());
+	return trimmedValue;
+}
+
+/**
+ * @brief Checks if the given string is empty or contains only whitespace characters.
+ * 
+ * @tparam T The typeparam; must be stringable.
+ * 
+ * @param str The string to check against.
+ * 
+ * @return true If the string is empty or consists only of whitespace.
+ * @return false Otherwise.
+ * 
+ * @copyright 2025 Procyon Systems Inh. Simon Cahill (s.cahill@procyon-systems.de)
+ */
+template<typename T>
+constexpr bool  isWhitespaceOrEmpty(const T& str) {
+	return std::all_of(str.begin(), str.end(), [](char c) { return std::isspace(c); });
+}
+
+/**
+ * @brief Swaps the endianness of a multi-byte value.
+ * 
+ * @tparam T The type of the value.
+ * @param value The value to swap.
+ * @return T The value with swapped endianness.
+ * 
+ * @copyright 2025 Procyon Systems Inh. Simon Cahill (s.cahill@procyon-systems.de)
+ */
+template<typename T>
+T                swapEndianness(T value) {
+	T swappedBytes;
+
+	char* valuePtr = reinterpret_cast<char*>(&value);
+	char* swappedPtr = reinterpret_cast<char*>(&swappedBytes);
+
+	auto sizeInBytes = sizeof(T);
+	for (size_t i = 0; i < sizeInBytes; i++) {
+		swappedPtr[sizeInBytes - 1 - i] = valuePtr[i];
+	}
+
+	return swappedBytes;
+}
+
 class String {
 public:
-	static std::string trim(const std::string& line);
+	static std::string trim(const std::string& line) { return Utils::trim(line); }
 
 	template<class Container>
 	static void split(const std::string& str, Container& cont, char delim = ' ') {

src/dbc.cpp

@@ -70,6 +70,24 @@ DbcParser::DbcParser()
 			  + whiteSpace + receiverPattern) {
 }
 
+#if __cplusplus >= 201703L
+void DbcParser::validate_dbc_file(const std::filesystem::path& file_path) {
+#else
+void DbcParser::validate_dbc_file(const std::string& file_path) {
+#endif // __cplusplus >= 201703L
+
+	std::ifstream testStream{file_path};
+
+	return validate_dbc_file(testStream);
+}
+
+void DbcParser::validate_dbc_file(std::istream& stream) {
+	stream.seekg(0, std::ios::beg);
+
+	DbcParser parser{};
+	parser.parse_dbc_header(stream);
+}
+
 void DbcParser::parse_file(std::istream& stream) {
 	std::string line;
 	std::vector<std::string> lines;
@@ -88,12 +106,9 @@ void DbcParser::parse_file(std::istream& stream) {
 }
 
 void DbcParser::parse_file(const std::string& file_name) {
-	auto extension = get_extension(file_name);
-	if (extension != ".dbc") {
-		throw NonDbcFileFormatError(file_name, extension);
-	}
+	validate_dbc_file(file_name);
 
-	std::ifstream stream(file_name.c_str());
+	std::ifstream stream(file_name);
 
 	parse_file(stream);
 }
@@ -107,19 +122,19 @@ std::string DbcParser::get_extension(const std::string& file_name) {
 	return "";
 }
 
-std::string DbcParser::get_version() const {
+const std::string& DbcParser::get_version() const {
 	return version;
 }
 
-std::vector<std::string> DbcParser::get_nodes() const {
+const std::vector<std::string>& DbcParser::get_nodes() const {
 	return nodes;
 }
 
-std::vector<Libdbc::Message> DbcParser::get_messages() const {
+const std::vector<Libdbc::Message>& DbcParser::get_messages() const {
 	return messages;
 }
 
-Message::ParseSignalsStatus DbcParser::parse_message(const uint32_t message_id, const std::vector<uint8_t>& data, std::vector<double>& out_values) {
+Message::ParseSignalsStatus DbcParser::parse_message(const uint32_t message_id, const std::vector<uint8_t>& data, std::vector<double>& out_values) const {
 	for (const auto& message : messages) {
 		if (message.id() == message_id) {
 			return message.parse_signals(data, out_values);
@@ -246,7 +261,7 @@ void DbcParser::parse_dbc_messages(const std::vector<std::string>& lines) {
 	}
 }
 
-std::vector<std::string> DbcParser::unused_lines() const {
+const std::vector<std::string>& DbcParser::unused_lines() const {
 	return missed_lines;
 }