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#define SOL_ALL_SAFETIES_ON 1
#include <sol/sol.hpp>
#include <iostream>
struct ree {
int value = 1;
ree() {
}
ree(int v) : value(v) {
}
};
int main() {
std::cout << "=== special pointers -- modify in place ==="
<< std::endl;
sol::state lua;
auto new_shared_ptr = [](sol::stack_reference obj) {
// works just fine
sol::stack::modify_unique_usertype(
obj, [](std::shared_ptr<ree>& sptr) {
sptr = std::make_shared<ree>(
sptr->value + 1);
});
};
auto reset_shared_ptr = [](sol::stack_reference obj) {
sol::stack::modify_unique_usertype(
obj, [](std::shared_ptr<ree>& sptr) {
// THIS IS SUCH A BAD IDEA AAAGH
sptr.reset();
// DO NOT reset to nullptr:
// change it to an actual NEW value...
// otherwise you will inject a nullptr into
// the userdata representation... which will
// NOT compare == to Lua's nil
});
};
lua.set_function("f", new_shared_ptr);
lua.set_function("f2", reset_shared_ptr);
lua.set_function("g",
[](ree* r) { std::cout << r->value << std::endl; });
lua["p"] = std::make_shared<ree>();
lua.script("g(p) -- okay");
lua.script("f(p)");
lua.script("g(p) -- okay");
// uncomment the below for
// segfault/read-access violation
lua.script("f2(p)");
// lua.script("g(p) -- kaboom");
return 0;
}
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