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#define SOL_ALL_SAFETIES_ON 1
#include <sol/sol.hpp>
#include <memory>
#include <iostream>
struct Shape {
virtual ~Shape() = default;
};
struct Box : Shape { };
SOL_BASE_CLASSES(Box, Shape);
SOL_DERIVED_CLASSES(Shape, Box);
int main() {
sol::state lua;
lua.open_libraries(sol::lib::base);
lua.new_usertype<Shape>("Shape", sol::no_constructor);
lua.new_usertype<Box>("Box", sol::factories([&]() {
auto b = std::make_shared<Box>();
std::cout << "create Box@" << std::hex << b.get()
<< '\n';
return b;
}));
lua.set_function(
"inspect_shape_table", [](const sol::table& args) {
std::shared_ptr<Shape> defbox = nullptr;
// check if there's a field with the name "shape"
auto s = args.get<
sol::optional<std::shared_ptr<Shape>>>(
"shape");
std::cout << "has : " << std::boolalpha
<< s.has_value() << '\n';
// get the field named "shape" or use the default
// value
std::cout << "get_or: " << std::hex
<< args.get_or<std::shared_ptr<Shape>>(
"shape", defbox)
.get()
<< '\n';
// this works but I can't test for existence
// beforehand...
std::cout
<< "get : " << std::hex
<< args.get<std::shared_ptr<Shape>>("shape")
.get()
<< '\n';
});
sol::protected_function_result result = lua.safe_script(
"inspect_shape_table({shape=Box.new()})");
SOL_ASSERT(result.valid());
return 0;
}
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