From 7fbc101a14177d89df1cef6e97bb488a52372f3f Mon Sep 17 00:00:00 2001
From: Vittorio Romeo <mail@vittorioromeo.com>
Date: Mon, 26 Jan 2026 14:35:59 +0100
Subject: [PATCH 1/2] Support parsing arbitrary duration representations

---
 include/rfl/parsing/Parser_duration.hpp | 29 ++++++++++++++-----------
 1 file changed, 16 insertions(+), 13 deletions(-)

diff --git a/include/rfl/parsing/Parser_duration.hpp b/include/rfl/parsing/Parser_duration.hpp
index 4656444b..2f205ded 100644
--- a/include/rfl/parsing/Parser_duration.hpp
+++ b/include/rfl/parsing/Parser_duration.hpp
@@ -99,43 +99,46 @@ struct Parser<R, W, std::chrono::duration<Rep, Period>, ProcessorsType> {
     }
   }
 
+  template <typename OtherDuration>
+  inline static constexpr bool samePeriodAs =
+      std::is_same_v<typename DurationType::period,
+                     typename OtherDuration::period>;
+
   static auto make_unit() noexcept {
-    if constexpr (std::is_same_v<DurationType, std::chrono::nanoseconds>) {
+    if constexpr (samePeriodAs<std::chrono::nanoseconds>) {
       return Unit::make<"nanoseconds">();
 
-    } else if constexpr (std::is_same_v<DurationType,
-                                        std::chrono::microseconds>) {
+    } else if constexpr (samePeriodAs<std::chrono::microseconds>) {
       return Unit::make<"microseconds">();
 
-    } else if constexpr (std::is_same_v<DurationType,
-                                        std::chrono::milliseconds>) {
+    } else if constexpr (samePeriodAs<std::chrono::milliseconds>) {
       return Unit::make<"milliseconds">();
 
-    } else if constexpr (std::is_same_v<DurationType, std::chrono::seconds>) {
+    } else if constexpr (samePeriodAs<std::chrono::seconds>) {
       return Unit::make<"seconds">();
 
-    } else if constexpr (std::is_same_v<DurationType, std::chrono::minutes>) {
+    } else if constexpr (samePeriodAs<std::chrono::minutes>) {
       return Unit::make<"minutes">();
 
-    } else if constexpr (std::is_same_v<DurationType, std::chrono::hours>) {
+    } else if constexpr (samePeriodAs<std::chrono::hours>) {
       return Unit::make<"hours">();
 
-    } else if constexpr (std::is_same_v<DurationType, std::chrono::days>) {
+    } else if constexpr (samePeriodAs<std::chrono::days>) {
       return Unit::make<"days">();
 
-    } else if constexpr (std::is_same_v<DurationType, std::chrono::weeks>) {
+    } else if constexpr (samePeriodAs<std::chrono::weeks>) {
       return Unit::make<"weeks">();
 
-    } else if constexpr (std::is_same_v<DurationType, std::chrono::months>) {
+    } else if constexpr (samePeriodAs<std::chrono::months>) {
       return Unit::make<"months">();
 
-    } else if constexpr (std::is_same_v<DurationType, std::chrono::years>) {
+    } else if constexpr (samePeriodAs<std::chrono::years>) {
       return Unit::make<"years">();
 
     } else {
       static_assert(always_false_v<DurationType>, "Unsupported type.");
     }
-  };
+  }
 };
 
 }  // namespace rfl::parsing

From 76c8ec6e988df3c54eff57d471a26233895e6002 Mon Sep 17 00:00:00 2001
From: Vittorio Romeo <mail@vittorioromeo.com>
Date: Tue, 27 Jan 2026 10:05:01 +0100
Subject: [PATCH 2/2] Add chrono duration test

---
 tests/json/test_chrono_duration.cpp | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)
 create mode 100644 tests/json/test_chrono_duration.cpp

diff --git a/tests/json/test_chrono_duration.cpp b/tests/json/test_chrono_duration.cpp
new file mode 100644
index 00000000..c78a11c7
--- /dev/null
+++ b/tests/json/test_chrono_duration.cpp
@@ -0,0 +1,29 @@
+#include <cassert>
+#include <chrono>
+#include <rfl.hpp>
+#include <rfl/json.hpp>
+#include <string>
+
+#include "write_and_read.hpp"
+
+namespace test_chrono_duration {
+
+struct TestStruct {
+  std::chrono::milliseconds ms_duration;
+
+  // Not std::chrono::seconds, but should be treated as such.
+  std::chrono::duration<int, std::ratio<1>> custom_duration;
+};
+
+TEST(json, test_chrono_duration) {
+  const auto test = TestStruct{
+      .ms_duration = std::chrono::milliseconds(1500),
+      .custom_duration = std::chrono::duration<int, std::ratio<1>>(10),
+  };
+
+  write_and_read(
+      test,
+      R"({"ms_duration":{"count":1500,"unit":"milliseconds"},"custom_duration":{"count":10,"unit":"seconds"}})");
+}
+
+}  // namespace test_chrono_duration