Is it possible to pass a C++ lambda as argument to a js function ?

[Delaunay]

Is the code below or equivalent possible ?
What is the best way to achieve this functionality ?

    class_<std::function<void()>>("_callback")
        .constructor<>()
        .function("opcall", &std::function<void()>::operator())
    ;

    emscripten::val window = emscripten::val::global("window");

    std::function<void()> wrapped = []() {
        std::cout << "Hello " << "\n";
    };

    emscripten::val intervalId = window.call<emscripten::val>("setInterval", wrapped, 1000);

The code below does not work on the js side. It is called periodically but produce an error on each call

Uncaught SyntaxError: missing ] after element list14 [lython.js line 3599 > Function:6:9](http://192.168.2.20:8000/build/Release/bin/lython.js%20line%203599%20%3E%20Function)note: [ opened at line 6, column 1

[brendandahl]

Lamdas are unfortunately not well supported at the moment in embind. There are a few open issues around workarounds on this, but you can do something like this:

int main() {
EM_ASM(
  globalThis.setIntervalWrapper = function(arg) {
    globalThis.setInterval(arg.opcall.bind(arg), 1000);
  };
);
    emscripten::val globalThis = emscripten::val::global("globalThis");

    std::function<void()> wrapped = []() {
        std::cout << "Hello " << "\n";
    };

    emscripten::val intervalId = globalThis.call<emscripten::val>("setIntervalWrapper", wrapped, 1000);
}

EMSCRIPTEN_BINDINGS(xxx) {
  class_<std::function<void()>>("_callback")
        .constructor<>()
        .function("opcall", &std::function<void()>::operator())
    ;
}