diff --git a/lemon/error.h b/lemon/error.h
--- a/lemon/error.h
+++ b/lemon/error.h
@@ -41,11 +41,11 @@
   ///
   class Exception : public std::exception {
   public:
-    ///\e Constructor
-    Exception() {}
-    ///\e Virtual destructor
+    ///Constructor
+    Exception() throw() {}
+    ///Virtual destructor
     virtual ~Exception() throw() {}
-    ///\e A short description of the exception
+    ///A short description of the exception
     virtual const char* what() const throw() {
       return "lemon::Exception";
     }
@@ -64,29 +64,31 @@
   public:
 
     /// Copy constructor
-    IoError(const IoError &error) {
+    IoError(const IoError &error) throw() : Exception() {
       message(error._message);
       file(error._file);
     }
 
     /// Constructor
-    explicit IoError(const char *message) {
+    explicit IoError(const char *message) throw() {
       IoError::message(message);
     }
 
     /// Constructor
-    explicit IoError(const std::string &message) {
+    explicit IoError(const std::string &message) throw() {
       IoError::message(message);
     }
 
     /// Constructor
-    IoError(const std::string &file, const char *message) {
+    explicit IoError(const char *message,
+                     const std::string &file) throw() {
       IoError::message(message);
       IoError::file(file);
     }
 
     /// Constructor
-    IoError(const std::string &file, const std::string &message) {
+    explicit IoError(const std::string &message,
+                     const std::string &file) throw() {
       IoError::message(message);
       IoError::file(file);
     }
@@ -95,53 +97,50 @@
     virtual ~IoError() throw() {}
 
     /// Set the error message
-    void message(const char *message) {
+    void message(const char *message) throw() {
       try {
         _message = message;
       } catch (...) {}
     }
 
     /// Set the error message
-    void message(const std::string& message) {
+    void message(const std::string& message) throw() {
       try {
         _message = message;
       } catch (...) {}
     }
 
     /// Set the file name
-    void file(const std::string &file) {
+    void file(const std::string &file) throw() {
       try {
         _file = file;
       } catch (...) {}
     }
 
     /// Returns the error message
-    const std::string& message() const {
+    const std::string& message() const throw() {
       return _message;
     }
 
     /// \brief Returns the filename
     ///
-    /// Returns the filename or empty string if the filename was not
-    /// specified.
-    const std::string& file() const {
+    /// Returns the filename or an empty string if it was not specified.
+    const std::string& file() const throw() {
       return _file;
     }
 
     /// \brief Returns a short error message
     ///
-    /// Returns a short error message which contains the message, the
-    /// file name and the line number.
+    /// Returns a short error message which contains the message and the
+    /// file name.
     virtual const char* what() const throw() {
       try {
         _what.clear();
         std::ostringstream oss;
         oss << "lemon:IoError" << ": ";
-        oss << message();
-        if (!file().empty()) {
-          oss << " (";
-          if (!file().empty()) oss << "with file '" << file() << "'";
-          oss << ")";
+        oss << _message;
+        if (!_file.empty()) {
+          oss << " ('" << _file << "')";
         }
         _what = oss.str();
       }
@@ -154,8 +153,8 @@
 
   /// \brief Format error
   ///
-  /// This class is used to indicate if an input file has wrong
-  /// formatting, or a data representation is not legal.
+  /// This exception is thrown when an input file has wrong
+  /// format or a data representation is not legal.
   class FormatError : public Exception {
   protected:
     std::string _message;
@@ -166,33 +165,35 @@
   public:
 
     /// Copy constructor
-    FormatError(const FormatError &error) {
+    FormatError(const FormatError &error) throw() : Exception() {
       message(error._message);
       file(error._file);
       line(error._line);
     }
 
     /// Constructor
-    explicit FormatError(const char *message) {
+    explicit FormatError(const char *message) throw() {
       FormatError::message(message);
       _line = 0;
     }
 
     /// Constructor
-    explicit FormatError(const std::string &message) {
+    explicit FormatError(const std::string &message) throw() {
       FormatError::message(message);
       _line = 0;
     }
 
     /// Constructor
-    FormatError(const std::string &file, int line, const char *message) {
+    explicit FormatError(const char *message,
+                         const std::string &file, int line = 0) throw() {
       FormatError::message(message);
       FormatError::file(file);
       FormatError::line(line);
     }
 
     /// Constructor
-    FormatError(const std::string &file, int line, const std::string &message) {
+    explicit FormatError(const std::string &message,
+                         const std::string &file, int line = 0) throw() {
       FormatError::message(message);
       FormatError::file(file);
       FormatError::line(line);
@@ -202,24 +203,24 @@
     virtual ~FormatError() throw() {}
 
     /// Set the line number
-    void line(int line) { _line = line; }
+    void line(int line) throw() { _line = line; }
 
     /// Set the error message
-    void message(const char *message) {
+    void message(const char *message) throw() {
       try {
         _message = message;
       } catch (...) {}
     }
 
     /// Set the error message
-    void message(const std::string& message) {
+    void message(const std::string& message) throw() {
       try {
         _message = message;
       } catch (...) {}
     }
 
     /// Set the file name
-    void file(const std::string &file) {
+    void file(const std::string &file) throw() {
       try {
         _file = file;
       } catch (...) {}
@@ -228,18 +229,17 @@
     /// \brief Returns the line number
     ///
     /// Returns the line number or zero if it was not specified.
-    int line() const { return _line; }
+    int line() const throw() { return _line; }
 
     /// Returns the error message
-    const std::string& message() const {
+    const std::string& message() const throw() {
       return _message;
     }
 
     /// \brief Returns the filename
     ///
-    /// Returns the filename or empty string if the filename was not
-    /// specified.
-    const std::string& file() const {
+    /// Returns the filename or an empty string if it was not specified.
+    const std::string& file() const throw() {
       return _file;
     }
 
@@ -252,12 +252,12 @@
         _what.clear();
         std::ostringstream oss;
         oss << "lemon:FormatError" << ": ";
-        oss << message();
-        if (!file().empty() || line() != 0) {
+        oss << _message;
+        if (!_file.empty() || _line != 0) {
           oss << " (";
-          if (!file().empty()) oss << "in file '" << file() << "'";
-          if (!file().empty() && line() != 0) oss << " ";
-          if (line() != 0) oss << "at line " << line();
+          if (!_file.empty()) oss << "in file '" << _file << "'";
+          if (!_file.empty() && _line != 0) oss << " ";
+          if (_line != 0) oss << "at line " << _line;
           oss << ")";
         }
         _what = oss.str();