--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dep/fmt/test/unicode-test.cc	Thu Jun 20 05:56:06 2024 -0400
@@ -0,0 +1,48 @@
+// Formatting library for C++ - Unicode tests
+//
+// Copyright (c) 2012 - present, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#include <iomanip>
+#include <locale>
+#include <vector>
+
+#include "fmt/chrono.h"
+#include "gmock/gmock.h"
+#include "util.h"  // get_locale
+
+using testing::Contains;
+
+TEST(unicode_test, is_utf8) { EXPECT_TRUE(fmt::detail::is_utf8()); }
+
+TEST(unicode_test, legacy_locale) {
+  auto loc = get_locale("be_BY.CP1251", "Belarusian_Belarus.1251");
+  if (loc == std::locale::classic()) return;
+
+  auto s = std::string();
+  try {
+    s = fmt::format(loc, "Дзень тыдня: {:L}", fmt::weekday(1));
+  } catch (const fmt::format_error& e) {
+    // Formatting can fail due to an unsupported encoding.
+    fmt::print("Format error: {}\n", e.what());
+    return;
+  }
+
+#if !FMT_GCC_VERSION || FMT_GCC_VERSION >= 500
+  auto&& os = std::ostringstream();
+  os.imbue(loc);
+  auto tm = std::tm();
+  tm.tm_wday = 1;
+  os << std::put_time(&tm, "%a");
+  auto wd = os.str();
+  if (wd == "??") {
+    EXPECT_EQ(s, "Дзень тыдня: ??");
+    fmt::print("std::locale gives ?? as a weekday.\n");
+    return;
+  }
+#endif
+  EXPECT_THAT((std::vector<std::string>{"Дзень тыдня: пн", "Дзень тыдня: Пан"}),
+              Contains(s));
+}