Add support for time points with arbitrary durations (fmtlib#2208)

jstaahl · Apr 2, 2021 · 06b3a10 · 06b3a10
1 parent dac42f5
commit 06b3a10
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Showing 2 changed files with 20 additions and 14 deletions.
diff --git a/include/fmt/chrono.h b/include/fmt/chrono.h
@@ -401,9 +401,9 @@ inline size_t strftime(wchar_t* str, size_t count, const wchar_t* format,
 }
 }  // namespace detail
 
-template <typename Char>
-struct formatter<std::chrono::time_point<std::chrono::system_clock>, Char>
-    : formatter<std::tm, Char> {
+template <typename Char, typename Duration>
+struct formatter<std::chrono::time_point<std::chrono::system_clock, Duration>,
+                 Char> : formatter<std::tm, Char> {
   template <typename FormatContext>
   auto format(std::chrono::time_point<std::chrono::system_clock> val,
               FormatContext& ctx) -> decltype(ctx.out()) {

diff --git a/test/chrono-test.cc b/test/chrono-test.cc
@@ -100,24 +100,30 @@ TEST(TimeTest, FormatTM) {
   std::time_t t = std::chrono::system_clock::to_time_t(point);
   std::tm tm = *std::localtime(&t);
   char strftime_output[256];
-  std::strftime(strftime_output, sizeof(strftime_output),
-                "%Y-%m-%d %H:%M:%S", &tm);
+  std::strftime(strftime_output, sizeof(strftime_output), "%Y-%m-%d %H:%M:%S",
+                &tm);
   EXPECT_EQ(strftime_output, fmt::format("{:%Y-%m-%d %H:%M:%S}", tm));
   auto wstrftime_output = std::wstring();
   std::copy(strftime_output, strftime_output + strlen(strftime_output),
             std::back_inserter(wstrftime_output));
-  EXPECT_EQ(wstrftime_output,
-            fmt::format(L"{:%Y-%m-%d %H:%M:%S}", tm));
+  EXPECT_EQ(wstrftime_output, fmt::format(L"{:%Y-%m-%d %H:%M:%S}", tm));
 }
 
-TEST(TimeTest, TimePoint) {
-  auto point = std::chrono::system_clock::now();
-  std::time_t t = std::chrono::system_clock::to_time_t(point);
+template <typename TimePoint> std::string strftime(TimePoint tp) {
+  std::time_t t = std::chrono::system_clock::to_time_t(tp);
   std::tm tm = *std::localtime(&t);
-  char strftime_output[256];
-  std::strftime(strftime_output, sizeof(strftime_output),
-                "%Y-%m-%d %H:%M:%S", &tm);
-  EXPECT_EQ(strftime_output, fmt::format("{:%Y-%m-%d %H:%M:%S}", point));
+  char output[256];
+  std::strftime(output, sizeof(output), "%Y-%m-%d %H:%M:%S", &tm);
+  return output;
+}
+
+TEST(TimeTest, TimePoint) {
+  auto t1 = std::chrono::system_clock::now();
+  EXPECT_EQ(strftime(t1), fmt::format("{:%Y-%m-%d %H:%M:%S}", t1));
+  using time_point =
+      std::chrono::time_point<std::chrono::system_clock, std::chrono::seconds>;
+  auto t2 = time_point(std::chrono::seconds(42));
+  EXPECT_EQ(strftime(t2), fmt::format("{:%Y-%m-%d %H:%M:%S}", t2));
 }
 
 #define EXPECT_TIME(spec, time, duration)                 \