gdextension++ (WIP: not ready, so don't look yet)

Abstracting away the ugly "GDExtensions" C api (and by extension some of Godot 🤐).

Differences to godot-cpp

• Method binds and class registration are all done at compile time. (0 allocation)
• Reimagined Variant (&co) interfaces that try to conform to standard container requirements.
• Lean and mean, by default only the bare minimum is available; ideal if you just want to bind an external library and don't want to compile a dozens of unrelated godot class bindings.
• Let's you bind arbitrary functions, meta data derived from arguments (see first point)
• Hand written variant types, only objects will be code generated (if you need them)

Goals

• Make writing C++ with godot actually enjoyable, inspired by the excellent godot-rust implementation.
• Fast compile times.
• Use C++20 and beyond, constexpr everything.

A little taste:

Inside our class registration function:

reg.register_method<"instance_method", [](Self* self, String text) {
    std::cout << "instance method!? " << self->instance_id() << "\n";

    for(auto c : text)
        std::cout << static_cast<char>(c) << "\n";
}>();

reg.register_method<"static_method", []() -> String {
    std::cout << "static method!?\n";

    return U"Yes we are unicode 🤖";
}>();

Yields us this in gdscript:

func _ready():
    var a = BasicExtension.new()
    a.instance_method("an instance method")
    
    print(BasicExtension.static_method())