+class InvalidSignerError : public std::runtime_error
+{
+public:
+ InvalidSignerError ();
+ InvalidSignerError (std::string reason);
+};
+
+class ProgrammingError : public std::runtime_error
+{
+public:
+ ProgrammingError (std::string file, int line);
+};
+
+class TextEncodingError : public std::runtime_error
+{
+public:
+ TextEncodingError (std::string s)
+ : std::runtime_error (s)
+ {}