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// Copyright 2019 The Emscripten Authors. All rights reserved.
// Emscripten is available under two separate licenses, the MIT license and the
// University of Illinois/NCSA Open Source License. Both these licenses can be
// found in the LICENSE file.
#include <stdio.h>
#include <emscripten.h>
#include <emscripten/bind.h>
#include <emscripten/val.h>
#include <type_traits>
#include <string>
using namespace emscripten;
// Class which wraps int and have no explicit or implicit conversions.
struct IntWrapper {
int get() const {
return value;
}
static IntWrapper create(int v) {
return IntWrapper(v);
}
private:
explicit IntWrapper(int v) : value(v) {}
int value;
};
// Need for SFINAE-based specialization testing.
template<typename T> struct IsIntWrapper : std::false_type {};
template<> struct IsIntWrapper<IntWrapper> : std::true_type {};
// We will pass IntWrapper between C++ and JavaScript via IntWrapperIntermediate
// which should be already registered by embind on both C++ and JavaScript sides.
// That way we can write C++ conversions only and use standard JS conversions.
using IntWrapperIntermediate = int;
// Specify custom (un)marshalling for all types satisfying IsIntWrapper.
namespace emscripten {
namespace internal {
// remove_cv/remove_reference are required for TypeID, but not BindingType, see https://github.com/emscripten-core/emscripten/issues/7292
template<typename T>
struct TypeID<T, typename std::enable_if<IsIntWrapper<typename std::remove_cv<typename std::remove_reference<T>::type>::type>::value, void>::type> {
static constexpr TYPEID get() {
return TypeID<IntWrapperIntermediate>::get();
}
};
template<typename T>
struct BindingType<T, typename std::enable_if<IsIntWrapper<T>::value, void>::type> {
typedef typename BindingType<IntWrapperIntermediate>::WireType WireType;
constexpr static WireType toWireType(const T& v) {
return BindingType<IntWrapperIntermediate>::toWireType(v.get());
}
constexpr static T fromWireType(WireType v) {
return T::create(BindingType<IntWrapperIntermediate>::fromWireType(v));
}
};
} // namespace internal
} // namespace emscripten
template<typename T>
void test() {
IntWrapper x = IntWrapper::create(10);
val js_func = val::module_property("js_func");
IntWrapper y = js_func(val(std::forward<T>(x))).as<IntWrapper>();
printf("C++ got %d\n", y.get());
}
int main(int argc, char **argv) {
test<IntWrapper>();
test<IntWrapper&>();
test<const IntWrapper>();
test<const IntWrapper&>();
return 0;
}
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