pad6 thread id and micros in formatter

include/spdlog/details/fmt_helper.h

@@ -86,6 +86,51 @@ inline void pad3(int n, fmt::memory_buffer &dest)
     fmt::format_to(dest, "{:03}", n);
 }
 
+inline void pad6(int n, fmt::memory_buffer &dest)
+{
+    if (n > 99999)
+    {
+        append_int(n, dest);
+        return;
+    }
+    if (n > 9999)
+    {
+        dest.push_back('0');
+    }
+    else if (n > 999)
+    {
+        dest.push_back('0');
+        dest.push_back('0');
+    }
+    else if (n > 99)
+    {
+        dest.push_back('0');
+        dest.push_back('0');
+        dest.push_back('0');
+    }
+    else if (n > 9)
+    {
+        dest.push_back('0');
+        dest.push_back('0');
+        dest.push_back('0');
+        dest.push_back('0');
+    }
+    else if (n >= 0)
+    {
+        dest.push_back('0');
+        dest.push_back('0');
+        dest.push_back('0');
+        dest.push_back('0');
+        dest.push_back('0');
+    }
+    else // negatives (unlikely, but just in case let fmt deal with it)
+    {
+        fmt::format_to(dest, "{:06}", n);
+        return;
+    }
+    append_int(n, dest);
+}
+
 } // namespace fmt_helper
 } // namespace details
 } // namespace spdlog
\ No newline at end of file

include/spdlog/details/pattern_formatter_impl.h

@@ -235,7 +235,7 @@ class f_formatter SPDLOG_FINAL : public flag_formatter
     {
         auto duration = msg.time.time_since_epoch();
         auto micros = std::chrono::duration_cast<std::chrono::microseconds>(duration).count() % 1000000;
-        fmt::format_to(dest, "{:06}", static_cast<int>(micros));
+        fmt_helper::pad6(static_cast<int>(micros), dest);
     }
 };
 
@@ -371,8 +371,8 @@ class t_formatter SPDLOG_FINAL : public flag_formatter
 {
     void format(const details::log_msg &msg, const std::tm &, fmt::memory_buffer &dest) override
     {
-        // fmt::format_to(dest, "{}", msg.thread_id);
-        fmt_helper::append_int(msg.thread_id, dest);
+
+        fmt_helper::pad6(msg.thread_id, dest);
     }
 };
 
@@ -390,7 +390,8 @@ class i_formatter SPDLOG_FINAL : public flag_formatter
 {
     void format(const details::log_msg &msg, const std::tm &, fmt::memory_buffer &dest) override
     {
-        fmt::format_to(dest, "{:06}", msg.msg_id);
+        // fmt::format_to(dest, "{:06}", msg.msg_id);
+        fmt_helper::pad6(msg.msg_id, dest);
     }
 };