Init cached_tm with {}

src/pattern_formatter.cpp

@@ -832,24 +832,24 @@ pattern_formatter::pattern_formatter(std::string pattern,
                                      pattern_time_type time_type,
                                      std::string eol,
                                      custom_flags custom_user_flags)
-    : pattern_(std::move(pattern)),
-      eol_(std::move(eol)),
-      pattern_time_type_(time_type),
-      need_localtime_(false),
-      last_log_secs_(0),
-      custom_handlers_(std::move(custom_user_flags)) {
-    std::memset(&cached_tm_, 0, sizeof(cached_tm_));
+    : pattern_{std::move(pattern)},
+      eol_{std::move(eol)},
+      pattern_time_type_{time_type},
+      need_localtime_{false},
+      cached_tm_{},
+      last_log_secs_{0},
+      custom_handlers_{std::move(custom_user_flags)} {
     compile_pattern_(pattern_);
 }
 
 // use by default full formatter for if pattern is not given
 pattern_formatter::pattern_formatter(pattern_time_type time_type, std::string eol)
-    : pattern_("%+"),
-      eol_(std::move(eol)),
-      pattern_time_type_(time_type),
-      need_localtime_(true),
-      last_log_secs_(0) {
-    std::memset(&cached_tm_, 0, sizeof(cached_tm_));
+    : pattern_{"%+"},
+      eol_{std::move(eol)},
+      pattern_time_type_{time_type},
+      need_localtime_{true},
+      cached_tm_{},
+      last_log_secs_{0} {
     formatters_.push_back(std::make_unique<details::full_formatter>(details::padding_info{}));
 }