use 'noexcept' instead of the deprecated 'throw()'

src/exceptions.h

@@ -26,9 +26,9 @@ class LAMMPSException : public std::exception {
 
   LAMMPSException(const std::string &msg) : message(msg) {}
 
-  ~LAMMPSException() throw() {}
+  ~LAMMPSException() noexcept {}
 
-  virtual const char *what() const throw() { return message.c_str(); }
+  virtual const char *what() const noexcept { return message.c_str(); }
 };
 
 class LAMMPSAbortException : public LAMMPSException {

src/file_writer.h

@@ -39,9 +39,9 @@ class FileWriterException : public std::exception {
  public:
   FileWriterException(const std::string &msg) : message(msg) {}
 
-  ~FileWriterException() throw() {}
+  ~FileWriterException() noexcept {}
 
-  virtual const char *what() const throw() { return message.c_str(); }
+  virtual const char *what() const noexcept { return message.c_str(); }
 };
 
 }    // namespace LAMMPS_NS

src/text_file_reader.h

@@ -52,9 +52,9 @@ class FileReaderException : public std::exception {
  public:
   FileReaderException(const std::string &msg) : message(msg) {}
 
-  ~FileReaderException() throw() {}
+  ~FileReaderException() noexcept {}
 
-  virtual const char *what() const throw() { return message.c_str(); }
+  virtual const char *what() const noexcept { return message.c_str(); }
 };
 
 class EOFException : public FileReaderException {

src/tokenizer.h

@@ -62,11 +62,11 @@ class TokenizerException : public std::exception {
    * \param  token  String of the token/word that caused the error */
   TokenizerException(const std::string &msg, const std::string &token);
 
-  ~TokenizerException() throw() {}
+  ~TokenizerException() noexcept {}
 
   /** Retrieve message describing the thrown exception
    * \return string with error message */
-  virtual const char *what() const throw() { return message.c_str(); }
+  virtual const char *what() const noexcept { return message.c_str(); }
 };
 
 class InvalidIntegerException : public TokenizerException {