diff options
Diffstat (limited to '3rdparty/sol2/docs/source/api/proxy.rst')
-rw-r--r-- | 3rdparty/sol2/docs/source/api/proxy.rst | 201 |
1 files changed, 0 insertions, 201 deletions
diff --git a/3rdparty/sol2/docs/source/api/proxy.rst b/3rdparty/sol2/docs/source/api/proxy.rst deleted file mode 100644 index 897dbbaf7dd..00000000000 --- a/3rdparty/sol2/docs/source/api/proxy.rst +++ /dev/null @@ -1,201 +0,0 @@ -proxy, (protected\_)function_result - proxy_base derivatives -============================================================ -``table[x]`` and ``function(...)`` conversion struct ----------------------------------------------------- - -.. code-block:: c++ - - template <typename Recurring> - struct proxy_base; - - template <typename Table, typename Key> - struct proxy : proxy_base<...>; - - struct stack_proxy: proxy_base<...>; - - struct function_result : proxy_base<...>; - - struct protected_function_result: proxy_base<...>; - - -These classes provide implicit assignment operator ``operator=`` (for ``set``) and an implicit conversion operator ``operator T`` (for ``get``) to support items retrieved from the underlying Lua implementation, specifically :doc:`sol::table<table>` and the results of function calls on :doc:`sol::function<function>` and :doc:`sol::protected_function<protected_function>`. - -.. _proxy: - -proxy ------ - -``proxy`` is returned by lookups into :doc:`sol::table<table>` and table-like entities. Because it is templated on key and table type, it would be hard to spell: you can capture it using the word ``auto`` if you feel like you need to carry it around for some reason before using it. ``proxy`` evaluates its arguments lazily, when you finally call ``get`` or ``set`` on it. Here are some examples given the following lua script. - -.. code-block:: lua - :linenos: - :caption: lua nested table script - - bark = { - woof = { - [2] = "arf!" - } - } - - -After loading that file in or putting it in a string and reading the string directly in lua (see :doc:`state`), you can start kicking around with it in C++ like so: - -.. code-block:: c++ - :linenos: - - sol::state lua; - - // produces proxy, implicitly converts to std::string, quietly destroys proxy - std::string x = lua["bark"]["woof"][2]; - - -``proxy`` lazy evaluation: - -.. code-block:: c++ - :linenos: - :caption: multi-get - - auto x = lua["bark"]; - auto y = x["woof"]; - auto z = x[2]; - // retrivies value inside of lua table above - std::string value = z; // "arf!" - // Can change the value later... - z = 20; - // Yay, lazy-evaluation! - int changed_value = z; // now it's 20! - - -We don't recommend the above to be used across classes or between function: it's more of something you can do to save a reference to a value you like, call a script or run a lua function, and then get it afterwards. You can also set functions (and function objects :ref:`*<note 1>`) this way, and retrieve them as well. - -.. code-block:: c++ - :linenos: - - lua["bark_value"] = 24; - lua["chase_tail"] = floof::chase_tail; // chase_tail is a free function - - -members -------- - -.. code-block:: c++ - :caption: functions: [overloaded] implicit conversion get - :name: implicit-get - - requires( sol::is_primitive_type<T>::value == true ) - template <typename T> - operator T() const; - - requires( sol::is_primitive_type<T>::value == false ) - template <typename T> - operator T&() const; - -Gets the value associated with the keys the proxy was generated and convers it to the type ``T``. Note that this function will always return ``T&``, a non-const reference, to types which are not based on :doc:`sol::reference<reference>` and not a :doc:`primitive lua type<types>` - -.. code-block:: c++ - :caption: function: get a value - :name: regular-get - - template <typename T> - decltype(auto) get( ) const; - -Gets the value associated with the keys and converts it to the type ``T``. - -.. code-block:: c++ - :caption: function: optionally get a value - :name: regular-get-or - - template <typename T, typename Otherwise> - optional<T> get_or( Otherwise&& otherise ) const; - -Gets the value associated with the keys and converts it to the type ``T``. If it is not of the proper type, it will return a ``sol::nullopt`` instead. - -``operator[]`` proxy-only members ---------------------------------- - -.. code-block:: c++ - :caption: function: valid - :name: proxy-valid - - bool valid () const; - -Returns whether this proxy actually refers to a valid object. It uses :ref:`sol::stack::probe_get_field<stack-probe-get-field>` to determine whether or not its valid. - -.. code-block:: c++ - :caption: functions: [overloaded] implicit set - :name: implicit-set - - requires( sol::detail::Function<Fx> == false ) - template <typename T> - proxy& operator=( T&& value ); - - requires( sol::detail::Function<Fx> == true ) - template <typename Fx> - proxy& operator=( Fx&& function ); - -Sets the value associated with the keys the proxy was generated with to ``value``. If this is a function, calls ``set_function``. If it is not, just calls ``set``. Does not exist on :ref:`function_result<function-result>` or :ref:`protected_function_result<protected-function-result>`. See :ref:`note<note 1>` for caveats. - -.. code-block:: c++ - :caption: function: set a callable - :name: regular-set-function - - template <typename Fx> - proxy& set_function( Fx&& fx ); - -Sets the value associated with the keys the proxy was generated with to a function ``fx``. Does not exist on :ref:`function_result<function-result>` or :ref:`protected_function_result<protected-function-result>`. - - -.. code-block:: c++ - :caption: function: set a value - :name: regular-set - - template <typename T> - proxy& set( T&& value ); - -Sets the value associated with the keys the proxy was generated with to ``value``. Does not exist on :ref:`function_result<function-result>` or :ref:`protected_function_result<protected-function-result>`. - -stack_proxy ------------ - -``sol::stack_proxy`` is what gets returned by :doc:`sol::variadic_args<variadic_args>` and other parts of the framework. It is similar to proxy, but is meant to alias a stack index and not a named variable. - -.. _function-result: - -function_result ---------------- - -``function_result`` is a temporary-only, intermediate-only implicit conversion worker for when :doc:`function<function>` is called. It is *NOT* meant to be stored or captured with ``auto``. It provides fast access to the desired underlying value. It does not implement ``set`` / ``set_function`` / templated ``operator=``, as is present on :ref:`proxy<proxy>`. - - -.. _protected-function-result: - -protected_function_result -------------------------- - -``protected_function_result`` is a nicer version of ``function_result`` that can be used to detect errors. Its gives safe access to the desired underlying value. It does not implement ``set`` / ``set_function`` / templated ``operator=`` as is present on :ref:`proxy<proxy>`. - - -.. _note 1: - -on function objects and proxies -------------------------------- - -Consider the following: - -.. code-block:: cpp - :linenos: - :caption: Note 1 Case - - struct doge { - int bark; - - void operator()() { - bark += 1; - } - }; - - sol::state lua; - lua["object"] = doge{}; // bind constructed doge to "object" - // but it binds as a function - -When you use the ``lua["object"] = doge{};`` from above, keep in mind that Sol detects if this is a function *callable with any kind of arguments*. Since ``doge`` has overriden ``return_type operator()( argument_types... )`` on itself, it results in satisfying the ``requires`` constraint from above. This means that if you have a user-defined type you want to bind as a :doc:`userdata with usertype semantics<usertype>` with this syntax, it might get bound as a function and not as a user-defined type (d'oh!). use ``lua["object"].set(doge)`` directly to avoid this, or ``lua["object"].set_function(doge{})`` to perform this explicitly.
\ No newline at end of file |