add noexcept checks, and some missing noexcepts

src/json.hpp

@@ -843,7 +843,8 @@ struct adl_serializer
     }
 
     template <typename Json, typename T>
-    static void to_json(Json& j, T&& val)
+    static void to_json(Json &j, T &&val) noexcept(
+        noexcept(::nlohmann::to_json(j, std::forward<T>(val))))
     {
       ::nlohmann::to_json(j, std::forward<T>(val));
     }

test/CMakeLists.txt

@@ -29,6 +29,7 @@ add_executable(${JSON_UNITTEST_TARGET_NAME}
     "src/unit-meta.cpp"
     "src/unit-modifiers.cpp"
     "src/unit-msgpack.cpp"
+    "src/unit-noexcept.cpp"
     "src/unit-pointer_access.cpp"
     "src/unit-readme.cpp"
     "src/unit-reference_access.cpp"

test/src/unit-noexcept.cpp

+#include "catch.hpp"
+
+#include "json.hpp"
+
+using nlohmann::json;
+
+enum test
+{
+};
+
+struct pod {};
+struct pod_bis {};
+
+void to_json(json &, pod) noexcept;
+void to_json(json &, pod_bis);
+static json j;
+
+static_assert(noexcept(json{}), "");
+static_assert(noexcept(nlohmann::to_json(j, 2)), "");
+static_assert(noexcept(nlohmann::to_json(j, 2.5)), "");
+static_assert(noexcept(nlohmann::to_json(j, true)), "");
+static_assert(noexcept(nlohmann::to_json(j, test{})), "");
+static_assert(noexcept(nlohmann::to_json(j, pod{})), "");
+static_assert(not noexcept(nlohmann::to_json(j, pod_bis{})), "");
+static_assert(noexcept(json(2)), "");
+static_assert(noexcept(json(test{})), "");
+static_assert(noexcept(json(pod{})), "");