Fix missing exports from json.cppm

docs/mkdocs/docs/features/modules.md

@@ -24,11 +24,21 @@ json data = json::parse(f);
 ```
 
 ## Modules do not export macros
-It should be noted that as modules do not export macros, the `nlohmann.json` module will not export any macros, but rather only the following symbols:
+It should be noted that as modules do not export macros, the `nlohmann.json` module will not export any macros.
 
+## Exported symbols
+Only the following symbols are exported from `nlohmann.json`:
 - `nlohmann::adl_serializer`
 - `nlohmann::basic_json`
 - `nlohmann::json`
 - `nlohmann::json_pointer`
-- `nlohmann::ordered_map`
 - `nlohmann::ordered_json`
+- `nlohmann::ordered_map`
+- `nlohmann::to_string`
+- `nlohmann::literals::json_literals::operator""_json`
+- `nlohmann::literals::json_literals::operator""_json_pointer`
+
+The following specialisations of `std` symbols are also exported:
+- `std::hash`
+- `std::less`
+- `std::swap`

src/modules/json.cppm

@@ -1,32 +1,50 @@
+//     __ _____ _____ _____
+//  __|  |   __|     |   | |  JSON for Modern C++
+// |  |  |__   |  |  | | | |  version 3.12.0
+// |_____|_____|_____|_|___|  https://github.com/nlohmann/json
+//
+// SPDX-FileCopyrightText: 2013-2026 Niels Lohmann <https://nlohmann.me>
+// SPDX-License-Identifier: MIT
+
 module;
 
 #include <nlohmann/json.hpp>
 
 export module nlohmann.json;
 
-export namespace nlohmann {
-    using ::nlohmann::adl_serializer;
-    using ::nlohmann::basic_json;
-    using ::nlohmann::json;
-    using ::nlohmann::json_pointer;
-    using ::nlohmann::ordered_json;
-    using ::nlohmann::ordered_map;
-}  // namespace nlohmann
-
+export
 NLOHMANN_JSON_NAMESPACE_BEGIN
 
+using NLOHMANN_JSON_NAMESPACE::adl_serializer;
+using NLOHMANN_JSON_NAMESPACE::basic_json;
+using NLOHMANN_JSON_NAMESPACE::json;
+using NLOHMANN_JSON_NAMESPACE::json_pointer;
+using NLOHMANN_JSON_NAMESPACE::ordered_json;
+using NLOHMANN_JSON_NAMESPACE::ordered_map;
+using NLOHMANN_JSON_NAMESPACE::to_string;
+
+inline namespace literals
+{
+inline namespace json_literals
+{
+    using NLOHMANN_JSON_NAMESPACE::literals::json_literals::operator""_json;
+    using NLOHMANN_JSON_NAMESPACE::literals::json_literals::operator""_json_pointer;
+} // namespace json_literals
+} // namespace literals
+
+// Note: the following nlohmann::detail symbols must be exported due to
+// an MSVC bug failing to compile without these symbols visible (ticket #3970)
 namespace detail
 {
-    export using NLOHMANN_JSON_NAMESPACE::detail::json_sax_dom_callback_parser;
-    export using NLOHMANN_JSON_NAMESPACE::detail::unknown_size;
+    using NLOHMANN_JSON_NAMESPACE::detail::json_sax_dom_callback_parser;
+    using NLOHMANN_JSON_NAMESPACE::detail::unknown_size;
 } // namespace detail
 
-export using NLOHMANN_JSON_NAMESPACE::adl_serializer;
-export using NLOHMANN_JSON_NAMESPACE::basic_json;
-export using NLOHMANN_JSON_NAMESPACE::json;
-export using NLOHMANN_JSON_NAMESPACE::json_pointer;
-export using NLOHMANN_JSON_NAMESPACE::ordered_json;
-export using NLOHMANN_JSON_NAMESPACE::ordered_map;
-export using NLOHMANN_JSON_NAMESPACE::to_string;
-
 NLOHMANN_JSON_NAMESPACE_END
+
+export namespace std
+{
+    using std::hash;
+    using std::less;
+    using std::swap;
+} // namespace std