Add utf-8 test for std::filesystem::path formatter.

Signed-off-by: Vladislav Shchapov <vladislav@shchapov.ru>

test/CMakeLists.txt

@@ -78,6 +78,9 @@ add_fmt_test(printf-test)
 add_fmt_test(ranges-test ranges-odr-test.cc)
 add_fmt_test(scan-test)
 add_fmt_test(std-test)
+if (MSVC)
+  target_compile_options(std-test PRIVATE /source-charset:utf-8)
+endif ()
 add_fmt_test(unicode-test HEADER_ONLY)
 if (MSVC)
   target_compile_options(unicode-test PRIVATE /utf-8)

test/std-test.cc

@@ -14,6 +14,11 @@ TEST(std_test, path) {
   EXPECT_EQ(fmt::format("{:8}", std::filesystem::path("foo")), "\"foo\"   ");
   EXPECT_EQ(fmt::format("{}", std::filesystem::path("foo\"bar.txt")),
             "\"foo\\\"bar.txt\"");
+
+#  ifdef _WIN32
+  EXPECT_EQ(fmt::format("{}", std::filesystem::path(L"Файл.txt")),
+            "\"\xd0\xa4\xd0\xb0\xd0\xb9\xd0\xbb.txt\"");
+#  endif
 #endif
 }