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diff --git a/3rdparty/sol2/docs/source/api/metatable_key.rst b/3rdparty/sol2/docs/source/api/metatable_key.rst deleted file mode 100644 index 718eb2b2ffc..00000000000 --- a/3rdparty/sol2/docs/source/api/metatable_key.rst +++ /dev/null @@ -1,154 +0,0 @@ -metatable_key -============= -A key for setting and getting an object's metatable ---------------------------------------------------- - -.. code-block:: cpp - - struct metatable_key_t {}; - const metatable_key_t metatable_key; - -You can use this in conjunction with :doc:`sol::table<table>` to set/get a metatable. Lua metatables are powerful ways to override default behavior of objects for various kinds of operators, among other things. Here is an entirely complete example, showing getting and working with a :doc:`usertype<usertype>`'s metatable defined by Sol: - -.. code-block:: cpp - :caption: messing with metatables - :linenos: - - #include <sol.hpp> - - int main () { - - struct bark { - int operator()(int x) { - return x; - } - }; - - sol::state lua; - lua.open_libraries(sol::lib::base); - - lua.new_usertype<bark>("bark", - sol::meta_function::call_function, &bark::operator() - ); - - bark b; - lua.set("b", &b); - - sol::table b_as_table = lua["b"]; - sol::table b_metatable = b_as_table[sol::metatable_key]; - sol::function b_call = b_metatable["__call"]; - sol::function b_as_function = lua["b"]; - - int result1 = b_as_function(1); - int result2 = b_call(b, 1); - // result1 == result2 == 1 - } - -It's further possible to have a "Dynamic Getter" (`thanks to billw2012 and Nava2 for this example`_!): - -.. code-block:: cpp - :caption: One way to make dynamic properties (there are others!) - :linenos: - - #include <sol.hpp> - #include <unordered_map> - - struct PropertySet { - sol::object get_property_lua(const char* name, sol::this_state s) - { - auto& var = props[name]; - return sol::make_object(s, var); - } - - void set_property_lua(const char* name, sol::stack_object object) - { - props[name] = object.as<std::string>(); - } - - std::unordered_map<std::string, std::string> props; - }; - - struct DynamicObject { - PropertySet& get_dynamic_props() { - return dynamic_props; - } - - PropertySet dynamic_props; - }; - - - int main () { - sol::state lua; - lua.open_libraries(sol::lib::base); - - lua.new_usertype<PropertySet>("PropertySet", - sol::meta_function::new_index, &PropertySet::set_property_lua, - sol::meta_function::index, &PropertySet::get_property_lua - ); - - lua.new_usertype<DynamicObject>("DynamicObject", - "props", sol::property(&DynamicObject::get_dynamic_props) - ); - - lua.script(R"( - obj = DynamicObject:new() - obj.props.name = 'test name' - print('name = ' .. obj.props.name) - )"); - - std::string name = lua["obj"]["props"]["name"]; - // name == "test name"; - } - - -You can even manipulate the ability to set and get items using metatable objects on a usertype or similar: - -.. code-block:: cpp - :caption: messing with metatables - vector type - :linenos: - - #include <sol.hpp> - - class vector { - public: - double data[3]; - - vector() : data{ 0,0,0 } {} - - double& operator[](int i) - { - return data[i]; - } - - - static double my_index(vector& v, int i) - { - return v[i]; - } - - static void my_new_index(vector& v, int i, double x) - { - v[i] = x; - } - }; - - int main () { - sol::state lua; - lua.open_libraries(sol::lib::base); - lua.new_usertype<vector>("vector", sol::constructors<sol::types<>>(), - sol::meta_function::index, &vector::my_index, - sol::meta_function::new_index, &vector::my_new_index); - lua.script("v = vector.new()\n" - "print(v[1])\n" - "v[2] = 3\n" - "print(v[2])\n" - ); - - vector& v = lua["v"]; - // v[0] == 0.0; - // v[1] == 0.0; - // v[2] == 3.0; - } - - -.. _thanks to billw2012 and Nava2 for this example: https://github.com/ThePhD/sol2/issues/71#issuecomment-225402055
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