Smart pointers and inheritance

[שחר לנגבהיים]

Hi,
I have a couple of structs objects, inheriting from a base struct, and 
passed using smart pointers. I've tried to bind them using embind, but when 
I look at the object in the debugger I see that it isn't a smart pointer 
but a raw pointer, and when I try to pass the object to another object, I 
get an error that the wrong type of object is passed. 

c++ code:
struct RenderModel {};

EMSCRIPTEN_BINDINGS(RenderModelBinding) {
emscripten::class_<RenderModel>("RenderModel")
.constructor<>()
.smart_ptr<std::shared_ptr<RenderModel>>("RenderModel");
}

struct GroupRenderModel : RenderModel {
void addModel(std::shared_ptr<wre_model::RenderModel> model) {
models.push_back(model);
}

std::vector<std::shared_ptr<wre_model::RenderModel>> models;
};

EMSCRIPTEN_BINDINGS(GroupRenderModelBinding) {
emscripten::class_<GroupRenderModel>("GroupRenderModel")
.constructor<>()
.function("addModel", &GroupRenderModel::addModel)
.smart_ptr<std::shared_ptr<GroupRenderModel>>("GroupRenderModel");
}

struct TextureRenderModel : public RenderModel {};

EMSCRIPTEN_BINDINGS(TextureRenderModelBinding) {
emscripten::class_<TextureRenderModel>("TextureRenderModel")
.constructor<>()
.smart_ptr<std::shared_ptr<TextureRenderModel>>("TextureRenderModel");
}

JS code: 
const groupLayer = new Module.GroupRenderModel();
const textureLayer = new Module.TextureRenderModel();
groupLayer.addModel(textureLayer);

When checking in the debugger, I see that groupLayer's pointer is:

   1. ptrType: RegisteredPointer
      1. destructorFunction: null
      2. isConst: false
      3. isReference: false
      4. isSmartPointer: false
      5. name: "GroupRenderModel*"
   
textureLayer's pointer is:

   1. ptrType: RegisteredPointer
      1. destructorFunction: null
      2. isConst: false
      3. isReference: false
      4. isSmartPointer: false
      5. name: "TextureRenderModel*"
   
And the error printed when calling setModel is:

   1. BindingError {name: "BindingError", message: "Expected null or 
   instance of RenderModel, got an instance of TextureRenderModel", stack: 
"BindingError: 
   Expected null or instance of 
   RenderM…ttp://localhost:51840/client.e31bb0bc.js:68387:15"}
   2. message: "Expected null or instance of RenderModel, got an instance 
   of TextureRenderModel"
      1. name: "BindingError"
      2. stack: "BindingError: Expected null or instance of RenderModel, 
      got an instance of TextureRenderModel↵ at BindingError.<anonymous> 
      (http://localhost:51840/render/appWASM.js:5207:24)↵ at new BindingError 
      (eval at createNamedFunction 
      (http://localhost:51840/render/appWASM.js:1:1), <anonymous>:4:34)↵ at 
      throwBindingError (http://localhost:51840/render/appWASM.js:5225:13)↵ at 
      upcastPointer (http://localhost:51840/render/appWASM.js:5569:15)↵ at 
      RegisteredPointer.genericPointerToWireType [as toWireType] 
      (http://localhost:51840/render/appWASM.js:5622:13)↵ at 
      GroupRenderModel$addModel [as addModel] (eval at new_ 
      (http://localhost:51840/render/appWASM.js:1:1), <anonymous>:9:26)↵ at 
      CompositionCanvas.updateRenderEngine 
      (http://localhost:51840/client.e31bb0bc.js:68401:18)↵ at 
      http://localhost:51840/client.e31bb0bc.js:68387:15";
      3. __proto__: Error
   

Using smart_ptr_constructor changes the value in isSmartPointer, but the 
same binding error is returned.

struct RenderModel {};

EMSCRIPTEN_BINDINGS(RenderModelBinding) {
emscripten::class_<RenderModel>("RenderModel")
.smart_ptr_constructor<std::shared_ptr<RenderModel>>("RenderModel",
&std::make_shared<RenderModel>);
}

struct GroupRenderModel : public RenderModel {
void addModel(std::shared_ptr<wre_model::RenderModel> model) {
models.push_back(model);
}

std::vector<std::shared_ptr<wre_model::RenderModel>> models;
};

EMSCRIPTEN_BINDINGS(GroupRenderModelBinding) {
emscripten::class_<GroupRenderModel>("GroupRenderModel")
.function("addModel", &GroupRenderModel::addModel)
.smart_ptr_constructor<std::shared_ptr<GroupRenderModel>>(
"GroupRenderModel", &std::make_shared<GroupRenderModel>);
}

struct TextureRenderModel : public RenderModel {};

EMSCRIPTEN_BINDINGS(TextureRenderModelBinding) {
emscripten::class_<TextureRenderModel>("TextureRenderModel")
.smart_ptr_constructor<std::shared_ptr<TextureRenderModel>>(
"TextureRenderModel", &std::make_shared<TextureRenderModel>);
}

Am I making some mistake with my binding declaration, or does embind not 
support implicit casting?


   1. 
      

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