include/wrenbind17/allocator.hpp #

#pragma once

#include <wren.hpp>

#include <string>

#include "index.hpp"
#include "pop.hpp"
#include "push.hpp"

namespace wrenbind17 {
    void setNextError(WrenVM* vm, std::string str);

#ifndef DOXYGEN_SHOULD_SKIP_THIS
    namespace detail {
        template <typename T, typename... Args> struct ForeignKlassAllocator {
            static T* ctor(Args&&... args) {
                return new T(std::forward<Args>(args)...);
            }
            template <size_t... Is> static T* ctorFrom(WrenVM* vm, detail::index_list<Is...>) {
                return ctor(PopHelper<Args>::f(vm, Is + 1)...);
            }
            static void allocate(WrenVM* vm) {
                auto* memory = wrenSetSlotNewForeign(vm, 0, 0, sizeof(ForeignObject<T>));
                new (memory) ForeignObject<T>();
                auto* wrapper = reinterpret_cast<ForeignObject<T>*>(memory);
                try {
                    wrapper->ptr.reset(ctorFrom(vm, detail::index_range<0, sizeof...(Args)>()));
                } catch (std::exception& e) {
                    wrenEnsureSlots(vm, 1);
                    wrenSetSlotString(vm, 0, e.what());
                    wrenAbortFiber(vm, 0);
                }
            }
            static void finalize(void* memory) {
                auto* wrapper = reinterpret_cast<ForeignObject<T>*>(memory);
                wrapper->~ForeignObject<T>();
            }
        };
    } // namespace detail
#endif
} // namespace wrenbind17