Changed the configure_loggers_from_file() function so that it throws a

specific exception rather than dlib::error upon encountering a problem.

--HG--
extra : convert_revision : svn%3Afdd8eb12-d10e-0410-9acb-85c331704f74/trunk%403745

dlib/logger/logger_config_file.cpp

@@ -146,7 +146,7 @@ namespace dlib
         ifstream fin(file_name.c_str());
 
         if (!fin)
-            throw error("logger_config: unable to open config file " + file_name);
+            throw logger_config_file_error("logger_config: unable to open config file " + file_name);
 
 
         cr_type main_cr;
@@ -181,7 +181,7 @@ namespace dlib
                     if (one == "file" && three.size() == 0)
                         set_all_logging_output_streams(get_file_stream(two));
                     else
-                        throw error("logger_config: invalid argument to output option: " + output);
+                        throw logger_config_file_error("logger_config: invalid argument to output option: " + output);
                 }
 
             } // if (cr.is_key_defined("output"))

dlib/logger/logger_config_file.h

@@ -12,6 +12,16 @@
 
 namespace dlib
 {
+    class logger_config_file_error : public error 
+    {
+        /*!
+            WHAT THIS OBJECT REPRESENTS
+                This is the exception class used by the configure_loggers_from_file()
+                function defined below.
+        !*/
+    public: 
+        logger_config_file_error(const std::string& s):error(s){}
+    };
 
     void configure_loggers_from_file (
         const std::string& file_name
@@ -20,7 +30,7 @@ namespace dlib
         ensures
             - configures the loggers with the contents of the file_name file
         throws
-            - dlib::error
+            - dlib::logger_config_file_error
                 this exception is thrown if there is a problem reading the config file
     !*/