Return buffer in duration.toString

Marlin/src/gcode/stats/M31.cpp

@@ -31,8 +31,8 @@
  */
 void GcodeSuite::M31() {
   char buffer[21];
-  duration_t elapsed = print_job_timer.duration();
-  elapsed.toString(buffer);
+  duration_t(print_job_timer.duration()).toString(buffer);
+
   ui.set_status(buffer);
 
   SERIAL_ECHO_START();

Marlin/src/lcd/extensible_ui/ui_api.cpp

@@ -842,8 +842,8 @@ namespace ExtUI {
   #if ENABLED(PRINTCOUNTER)
     char* getTotalPrints_str(char buffer[21])    { strcpy(buffer,i16tostr3left(print_job_timer.getStats().totalPrints));    return buffer; }
     char* getFinishedPrints_str(char buffer[21]) { strcpy(buffer,i16tostr3left(print_job_timer.getStats().finishedPrints)); return buffer; }
-    char* getTotalPrintTime_str(char buffer[21]) { duration_t(print_job_timer.getStats().printTime).toString(buffer);       return buffer; }
-    char* getLongestPrint_str(char buffer[21])   { duration_t(print_job_timer.getStats().longestPrint).toString(buffer);    return buffer; }
+    char* getTotalPrintTime_str(char buffer[21]) { return duration_t(print_job_timer.getStats().printTime).toString(buffer); }
+    char* getLongestPrint_str(char buffer[21])   { return duration_t(print_job_timer.getStats().longestPrint).toString(buffer); }
     char* getFilamentUsed_str(char buffer[21])   {
       printStatistics stats = print_job_timer.getStats();
       sprintf_P(buffer, PSTR("%ld.%im"), long(stats.filamentUsed / 1000), int16_t(stats.filamentUsed / 100) % 10);

Marlin/src/lcd/menu/menu_info.cpp

@@ -59,40 +59,29 @@
     STATIC_PAIR(MSG_INFO_PRINT_COUNT, i16tostr3left(stats.totalPrints), false);                    // Print Count: 999
     STATIC_PAIR(MSG_INFO_COMPLETED_PRINTS, i16tostr3left(stats.finishedPrints), false);            // Completed  : 666
 
-    duration_t elapsed = stats.printTime;
-    elapsed.toString(buffer);
-
     STATIC_PAIR_P(MSG_INFO_PRINT_TIME, "", false);                                                 // Total print Time:
-    STATIC_ITEM("> ", false, false, buffer);                                                       // > 99y 364d 23h 59m 59s
+    STATIC_ITEM("> ", false, false, duration_t(stats.printTime).toString(buffer));                 // > 99y 364d 23h 59m 59s
 
     STATIC_PAIR_P(MSG_INFO_PRINT_LONGEST, "", false);                                              // Longest job time:
-    elapsed = stats.longestPrint;
-    elapsed.toString(buffer);
-    STATIC_ITEM("> ", false, false, buffer);                                                       // > 99y 364d 23h 59m 59s
+    STATIC_ITEM("> ", false, false, duration_t(stats.longestPrint).toString(buffer));              // > 99y 364d 23h 59m 59s
 
     STATIC_PAIR_P(MSG_INFO_PRINT_FILAMENT, "", false);                                             // Extruded total:
     sprintf_P(buffer, PSTR("%ld.%im"), long(stats.filamentUsed / 1000), int16_t(stats.filamentUsed / 100) % 10);
     STATIC_ITEM("> ", false, false, buffer);                                                       // > 125m
 
     #if SERVICE_INTERVAL_1 > 0
-      elapsed = stats.nextService1;
-      elapsed.toString(buffer);
       STATIC_ITEM(SERVICE_NAME_1 MSG_SERVICE_IN, false, false);                                    // Service X in:
-      STATIC_ITEM("> ", false, false, buffer);                                                     // > 7d 12h 11m 10s
+      STATIC_ITEM("> ", false, false, duration_t(stats.nextService1).toString(buffer));            // > 7d 12h 11m 10s
     #endif
 
     #if SERVICE_INTERVAL_2 > 0
-      elapsed = stats.nextService2;
-      elapsed.toString(buffer);
       STATIC_ITEM(SERVICE_NAME_2 MSG_SERVICE_IN, false, false);
-      STATIC_ITEM("> ", false, false, buffer);
+      STATIC_ITEM("> ", false, false, duration_t(stats.nextService2).toString(buffer));
     #endif
 
     #if SERVICE_INTERVAL_3 > 0
-      elapsed = stats.nextService3;
-      elapsed.toString(buffer);
       STATIC_ITEM(SERVICE_NAME_3 MSG_SERVICE_IN, false, false);
-      STATIC_ITEM("> ", false, false, buffer);
+      STATIC_ITEM("> ", false, false, duration_t(stats.nextService3).toString(buffer));
     #endif
 
     END_SCREEN();

Marlin/src/libs/duration_t.h

@@ -120,7 +120,7 @@ struct duration_t {
    *  59m 59s
    *  59s
    */
-  void toString(char *buffer) const {
+  char* toString(char * const buffer) const {
     int y = this->year(),
         d = this->day() % 365,
         h = this->hour() % 24,
@@ -132,6 +132,7 @@ struct duration_t {
     else if (h) sprintf_P(buffer, PSTR("%ih %im %is"), h, m, s);
     else if (m) sprintf_P(buffer, PSTR("%im %is"), m, s);
     else sprintf_P(buffer, PSTR("%is"), s);
+    return buffer;
   }
 
   /**

Marlin/src/module/printcounter.cpp

@@ -183,11 +183,9 @@ void PrintCounter::saveStats() {
 
 #if HAS_SERVICE_INTERVALS
   inline void _service_when(char buffer[], const char * const msg, const uint32_t when) {
-    duration_t elapsed = when;
-    elapsed.toString(buffer);
     SERIAL_ECHOPGM(MSG_STATS);
     serialprintPGM(msg);
-    SERIAL_ECHOLNPAIR(" in ", buffer);
+    SERIAL_ECHOLNPAIR(" in ", duration_t(when).toString(buffer));
   }
 #endif