reflector

NOTE: This is still a work in progress. Right now the tool mostly works, but is imperfect, generates imperfect code, and has bugs. Use at your own risk.

Pull requests welcomed and encouraged and begged for!

What is it?

Reflector is a C++20 reflection generation tool similar to the Unreal Header Tool. It will scan the headers in your codebase for types/methods/fields annotated with a special reflection syntax, and create files containing reflection information about those entities. The main type of file it will create is the *.mirror file, which you are meant to include in the files Reflector is scanning. This will inject reflection information straight into your files, allowing for compile-time reflection of these entities.

#include "Component.h.mirror"

RClass(); /// Annotation will cause the class below to be reflected
class Component : public Reflector::Reflectable
{
	RBody(); /// Required in every reflected class

	RField(Required, Setter = false, Editor = false); /// Annotation will cause Name to be reflected
	std::string Name; 

	/// ^ The Name field will be required when deserializing, will not be settable
	/// from scripts, and will not be editable in the editor.

	/// These comment lines will be included in the auto-generated documentation
	/// for SetName. The `ScriptPrivate` attribute means that this function will
	/// not be callable from script. 
	RMethod(ScriptPrivate); /// Annotation will cause SetName to be reflected
	void SetName(std::string_view name) { if (VerifyName(name)) Name = name; }
	
protected:

	/// This field will be reflected, and a public GetParentObject function will 
	/// be generated for it.
	RField();
	class Object* mParentObject = nullptr;
};

REnum();
enum class TestEnum
{
	Open = 5,
	
	Visible,

	REnumerator(Opposite = Dead);
	Alive,
};

How to use

See Usage in the wiki.

Example

See the example in the wiki.

Dependencies

Projects Using Reflector

• C++20 (C++17 support could be added if requested)
• optional nlohmann/json if you want out-of-the-box JSON serialization support

The Reflector Tool Itself

• C++20
• nlohmann/json
• magic_enum
• tl::expected - or std::expected if it's available to your compiler
• my personal header_utils library

See the vcpkg.json file for up-to date dependency information.

UNTODO

These are things I am not planning on doing unless someone asks nicely:

• support for generating code for older C++ versions
• other platforms (the code is fairly portable, just needs the memory mapping code to be written for non-windows platforms)
• scriptability/pluginability