property

wrapper to specify read and write variable functionality using functions

template <typename Read, typename Write>
decltype(auto) property ( Read&& read_function, Write&& write_function );
template <typename Read>
decltype(auto) property ( Read&& read_function );
template <typename Write>
decltype(auto) property ( Write&& write_function );

These set of functions create a type which allows a setter and getter pair (or a single getter, or a single setter) to be used to create a variable that is either read-write, read-only, or write-only. When used during usertype construction, it will create a variable that uses the setter/getter member function specified.

#define SOL_ALL_SAFETIES_ON 1
#include <sol/sol.hpp>


#include <iostream>

class Player {
public:
	int get_hp() const {
		return hp;
	}

	void set_hp(int value) {
		hp = value;
	}

	int get_max_hp() const {
		return maxhp;
	}

	void set_max_hp(int value) {
		maxhp = value;
	}

private:
	int hp = 50;
	int maxhp = 50;
};

int main(int, char*[]) {

	std::cout << "=== properties from C++ functions ==="
	          << std::endl;

	sol::state lua;
	lua.open_libraries(sol::lib::base);

	lua.set("theplayer", Player());

	// Yes, you can register after you set a value and it will
	// connect up the usertype automatically
	lua.new_usertype<Player>("Player",
	     "hp",
	     sol::property(&Player::get_hp, &Player::set_hp),
	     "maxHp",
	     sol::property(
	          &Player::get_max_hp, &Player::set_max_hp));

	const auto& code = R"(
	-- variable syntax, calls functions
	theplayer.hp = 20
	print('hp:', theplayer.hp)
	print('max hp:', theplayer.maxHp)
	)";

	lua.script(code);

	return 0;
}