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#define SOL_ALL_SAFETIES_ON 1
#include <sol/sol.hpp>
#include <iostream>
struct Doge {
int tailwag = 50;
Doge() {
}
Doge(int wags) : tailwag(wags) {
}
~Doge() {
std::cout << "Dog at " << this
<< " is being destroyed..." << std::endl;
}
};
int main(int, char*[]) {
std::cout << "=== userdata memory reference ==="
<< std::endl;
sol::state lua;
lua.open_libraries(sol::lib::base);
Doge dog {}; // Kept alive somehow
// Later...
// The following stores a reference, and does not copy/move
// lifetime is same as dog in C++
// (access after it is destroyed is bad)
lua["dog"] = &dog;
// Same as above: respects std::reference_wrapper
lua["dog"] = std::ref(dog);
// These two are identical to above
lua.set("dog", &dog);
lua.set("dog", std::ref(dog));
Doge& dog_ref = lua["dog"]; // References Lua memory
Doge* dog_pointer = lua["dog"]; // References Lua memory
Doge dog_copy = lua["dog"]; // Copies, will not affect lua
lua.new_usertype<Doge>("Doge", "tailwag", &Doge::tailwag);
dog_copy.tailwag = 525;
// Still 50
lua.script("assert(dog.tailwag == 50)");
dog_ref.tailwag = 100;
// Now 100
lua.script("assert(dog.tailwag == 100)");
dog_pointer->tailwag = 345;
// Now 345
lua.script("assert(dog.tailwag == 345)");
std::cout << std::endl;
return 0;
}
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