Add std::locale support to std::tm formatter

fmtlib · Oct 17, 2021 · f8410da · f8410da
1 parent bbbb51d
commit f8410da
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Showing 2 changed files with 11 additions and 1 deletion.
diff --git a/include/fmt/chrono.h b/include/fmt/chrono.h
@@ -1708,7 +1708,9 @@ template <typename Char> struct formatter<std::tm, Char> {
   template <typename FormatContext>
   auto format(const std::tm& tm, FormatContext& ctx) const
       -> decltype(ctx.out()) {
-    const auto& loc = std::locale::classic();
+    const auto& loc_ref = ctx.locale();
+    const auto& loc =
+        loc_ref ? loc_ref.template get<std::locale>() : std::locale::classic();
     auto w = detail::tm_writer<decltype(ctx.out()), Char>(loc, ctx.out(), tm);
     if (spec_ == spec::year_month_day)
       w.on_iso_date();

diff --git a/test/chrono-test.cc b/test/chrono-test.cc
@@ -529,10 +529,18 @@ TEST(chrono_test, weekday) {
   auto loc = get_locale("ru_RU.UTF-8");
   std::locale::global(loc);
   auto mon = fmt::weekday(1);
+
+  auto tm = std::tm();
+  tm.tm_wday = static_cast<int>(mon.c_encoding());
+
   EXPECT_EQ(fmt::format("{}", mon), "Mon");
+  EXPECT_EQ(fmt::format("{:%a}", tm), "Mon");
+
   if (loc != std::locale::classic()) {
     EXPECT_THAT((std::vector<std::string>{"пн", "Пн", "пнд", "Пнд"}),
                 Contains(fmt::format(loc, "{:L}", mon)));
+    EXPECT_THAT((std::vector<std::string>{"пн", "Пн", "пнд", "Пнд"}),
+                Contains(fmt::format(loc, "{:%a}", tm)));
   }
 }