Added set_all_logging_headers()

dlib/logger/logger_kernel_1.cpp

@@ -47,6 +47,21 @@ namespace dlib
         gd.set_level("",new_level);
     }
 
+    void set_all_logging_headers (
+        const print_header_type& new_header
+    )
+    {
+        logger::global_data& gd = logger::get_global_data();
+        auto_mutex M(gd.m);
+        gd.loggers.reset();
+        while (gd.loggers.move_next())
+        {
+            gd.loggers.element()->print_header = new_header;
+        }
+
+        gd.set_logger_header("",new_header);
+    }
+
 // ----------------------------------------------------------------------------------------
 
     namespace logger_helper_stuff
@@ -300,7 +315,7 @@ namespace dlib
 
 // ----------------------------------------------------------------------------------------
 
-    logger::print_header_type logger::global_data::
+    print_header_type logger::global_data::
     logger_header (
         const std::string& name
     )

dlib/logger/logger_kernel_1.h

@@ -70,6 +70,17 @@ namespace dlib
         const log_level& new_level
     );
 
+    typedef void (*print_header_type)(
+        std::ostream& out, 
+        const std::string& logger_name, 
+        const log_level& l,
+        const uint64 thread_id
+    );
+
+    void set_all_logging_headers (
+        const print_header_type& new_header
+    );
+
 // ----------------------------------------------------------------------------------------
 
     void print_default_logger_header (
@@ -352,13 +363,6 @@ namespace dlib
             gd.set_output_hook(logger_name, hook);
         }
 
-        typedef void (*print_header_type)(
-            std::ostream& out, 
-            const std::string& logger_name, 
-            const log_level& l,
-            const uint64 thread_id
-        );
-
         print_header_type logger_header (
         ) const { return print_header; }
 
@@ -602,6 +606,10 @@ namespace dlib
             const log_level& new_level
         );
 
+        friend void set_all_logging_headers (
+            const print_header_type& new_header 
+        );
+
         friend void set_all_logging_output_streams (
             std::ostream& out
         );

dlib/logger/logger_kernel_abstract.h

@@ -79,6 +79,26 @@ namespace dlib
             - std::bad_alloc
     !*/
 
+// ----------------------------------------------------------------------------------------
+
+    typedef void (*print_header_type)(
+        std::ostream& out, 
+        const std::string& logger_name, 
+        const log_level& l,
+        const uint64 thread_id
+    );
+
+    void set_all_logging_headers (
+        const print_header_type& new_header
+    );
+    /*!
+        ensures
+            - for all loggers L (even loggers not yet constructed):
+                - #L.logger_header() == new_header 
+        throws
+            - std::bad_alloc
+    !*/
+
 // ----------------------------------------------------------------------------------------
 
     template <
@@ -361,13 +381,6 @@ namespace dlib
                 - std::bad_alloc
         !*/
 
-        typedef void (*print_header_type)(
-                std::ostream& out, 
-                const std::string& logger_name, 
-                const log_level& l,
-                const uint64 thread_id
-                );
-
         print_header_type logger_header (
         ) const;
         /*!