Add support for C++ modules

Author: mikomikotaishi

CMakeLists.txt

@@ -23,6 +23,7 @@ option(REFLECTCPP_YAML "Enable YAML support" ${REFLECTCPP_ALL_FORMATS})
 option(REFLECTCPP_BUILD_BENCHMARKS "Build benchmarks" OFF)
 option(REFLECTCPP_BUILD_TESTS "Build tests" OFF)
 option(REFLECTCPP_CHECK_HEADERS "Make sure that all headers are self-contained" OFF)
+option(REFLECTCPP_BUILD_MODULES "Build reflectcpp as a C++ module" OFF)
 
 option(REFLECTCPP_USE_BUNDLED_DEPENDENCIES "Use the bundled dependencies" ON)
 
@@ -446,6 +447,10 @@ if(REFLECTCPP_CHECK_HEADERS)
     endforeach()
 endif()
 
+if (REFLECTCPP_BUILD_MODULES)
+    add_subdirectory(src/modules)
+endif()
+
 if (REFLECTCPP_INSTALL)
     include(GNUInstallDirs)
     include(CMakePackageConfigHelpers)

README.md

@@ -587,6 +587,33 @@ In addition, it supports the following custom containers:
 
 Finally, it is very easy to extend full support to your own classes, refer to the [documentation](https://rfl.getml.com/docs-readme) for details.
 
+### Module support
+
+reflect-cpp has support for C++20 modules. To enable, pass `REFLECTCPP_BUILD_MODULES` to CMake. You must have CMake 3.28 or higher, and any build system that supports modules (such as Ninja).
+
+```cpp
+import std;
+import rfl;
+
+using std::string;
+
+struct Person {
+    string first_name;
+    string last_name;
+    int age;
+};
+
+const Person homer = Person{
+    .first_name = "Homer",
+    .last_name = "Simpson",
+    .age = 45
+};
+
+// We can now write into and read from a JSON string.
+const string json_string = rfl::json::write(homer);
+auto homer2 = rfl::json::read<Person>(json_string).value();
+```
+
 
 ## Installation
 

include/rfl/capnproto/schema/CapnProtoTypes.hpp

@@ -16,7 +16,7 @@ struct CapnProtoTypes {
   std::map<std::string, schema::Type> unions_;
 };
 
-const char* MAP_DEFINITION = R"(
+inline const char* MAP_DEFINITION = R"(
 struct Map(Value) {
   entries @0 :List(Entry);
   struct Entry {

include/rfl/parsing/call_destructors_on_array_where_necessary.hpp

@@ -1,3 +1,4 @@
+
 #ifndef RFL_PARSING_CALL_DESTRUCTORS_ON_ARRAY_WHERE_NECESSARY_HPP_
 #define RFL_PARSING_CALL_DESTRUCTORS_ON_ARRAY_WHERE_NECESSARY_HPP_
 

src/modules/CMakeLists.txt

@@ -0,0 +1,42 @@
+cmake_minimum_required(VERSION 3.28)
+
+add_library(reflectcpp_module)
+
+target_sources(reflectcpp_module
+    PUBLIC
+        FILE_SET CXX_MODULES FILES
+            rfl.cppm
+            rfl.avro.cppm
+            rfl.bson.cppm
+            rfl.capnproto.cppm
+            rfl.cbor.cppm
+            rfl.csv.cppm
+            rfl.flexbuf.cppm
+            rfl.json.cppm
+            rfl.msgpack.cppm
+            rfl.parquet.cppm
+            rfl.toml.cppm
+            rfl.ubjson.cppm
+            rfl.xml.cppm
+            rfl.yaml.cppm
+)
+
+target_compile_features(reflectcpp_module PUBLIC cxx_std_23)
+
+target_include_directories(reflectcpp_module PUBLIC
+    $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/include>
+    $<INSTALL_INTERFACE:include>
+)
+
+target_link_libraries(reflectcpp_module PUBLIC reflectcpp::reflectcpp)
+
+add_library(reflectcpp::module ALIAS reflectcpp_module)
+
+# Installation
+install(TARGETS reflectcpp_module
+    EXPORT ${PROJECT_NAME}Targets
+    LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
+    ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
+    RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
+    FILE_SET CXX_MODULES DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/src/module
+)

src/modules/rfl.avro.cppm

@@ -0,0 +1,26 @@
+module;
+
+#include "rfl/avro.hpp"
+#include "rfl/avro/schema/Type.hpp"
+
+export module rfl:avro;
+
+export namespace rfl::avro {
+    using rfl::avro::Parser;
+    using rfl::avro::Reader;
+    using rfl::avro::Schema;
+    using rfl::avro::Writer;
+    using rfl::avro::InputObjectType;
+    using rfl::avro::InputVarType;
+
+    using rfl::avro::load;
+    using rfl::avro::read;
+    using rfl::avro::save;
+    using rfl::avro::to_json_representation;
+    using rfl::avro::to_schema;
+    using rfl::avro::write;
+
+    namespace schema {
+        using rfl::avro::schema::Type;
+    }
+}

src/modules/rfl.bson.cppm

@@ -0,0 +1,18 @@
+module;
+
+#include "rfl/bson.hpp"
+
+export module rfl:bson;
+
+export namespace rfl::bson {
+    using rfl::bson::Parser;
+    using rfl::bson::Reader;
+    using rfl::bson::Writer;
+    using rfl::bson::InputObjectType;
+    using rfl::bson::InputVarType;
+
+    using rfl::bson::load;
+    using rfl::bson::read;
+    using rfl::bson::save;
+    using rfl::bson::write;
+}

src/modules/rfl.capnproto.cppm

@@ -0,0 +1,37 @@
+module;
+
+#include "rfl/capnproto.hpp"
+#include "rfl/capnproto/is_named_type.hpp"
+#include "rfl/capnproto/schema/CapnProtoTypes.hpp"
+
+export module rfl:capnproto;
+
+export namespace rfl::capnproto {
+    using rfl::capnproto::Parser;
+    using rfl::capnproto::Reader;
+    using rfl::capnproto::Schema;
+    using rfl::capnproto::SchemaImpl;
+    using rfl::capnproto::SchemaHolder;
+    using rfl::capnproto::Writer;
+    using rfl::capnproto::InputObjectType;
+    using rfl::capnproto::InputVarType;
+
+    using rfl::capnproto::load;
+    using rfl::capnproto::read;
+    using rfl::capnproto::save;
+    using rfl::capnproto::to_schema;
+    using rfl::capnproto::write;
+    using rfl::capnproto::get_root_name;
+    using rfl::capnproto::is_named_type;
+    using rfl::capnproto::to_string_representation;
+    using rfl::capnproto::to_schema;
+
+    namespace schema {
+        using rfl::capnproto::schema::CapnProtoTypes;
+        using rfl::capnproto::schema::Type;
+
+        using rfl::capnproto::schema::MAP_DEFINITION;
+
+        using rfl::capnproto::schema::operator<<;
+    }
+}

src/modules/rfl.cbor.cppm

@@ -0,0 +1,18 @@
+module;
+
+#include "rfl/cbor.hpp"
+
+export module rfl:cbor;
+
+export namespace rfl::cbor {
+    using rfl::cbor::Parser;
+    using rfl::cbor::Reader;
+    using rfl::cbor::Writer;
+    using rfl::cbor::InputObjectType;
+    using rfl::cbor::InputVarType;
+
+    using rfl::cbor::load;
+    using rfl::cbor::read;
+    using rfl::cbor::save;
+    using rfl::cbor::write;
+}