h1-mod/deps/sol2/documentation/source/api/as_table.rst
2024-03-07 00:54:32 -05:00

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as_table
===========
*make sure an object is pushed as a table*
.. code-block:: cpp
template <typename T>
as_table_t {
T& value() &;
const T& value() & const;
T&& value() &&;
};
template <typename T>
as_table_t<T> as_function ( T&& container );
This function serves the purpose of ensuring that an object is pushed -- if possible -- like a table into Lua. The container passed here can be a pointer, a reference, a ``std::reference_wrapper`` around a container, or just a plain container value. It must have a begin/end function, and if it has a ``std::pair<Key, Value>`` as its ``value_type``, it will be pushed as a dictionary. Otherwise, it's pushed as a sequence.
.. literalinclude:: ../../../examples/source/docs/as_table_ipairs.cpp
:linenos:
Note that any caveats with Lua tables apply the moment it is serialized, and the data cannot be gotten out back out in C++ as a C++ type. You can deserialize the Lua table into something explicitly using the ``sol::as_table_t`` marker for your get and conversion operations using sol. At that point, the returned type is deserialized **from** a table, meaning you cannot reference any kind of C++ data directly as you do with regular userdata/usertypes. *All C++ type information is lost upon serialization into Lua.*
If you need this functionality with a member variable, use a :doc:`property on a getter function<property>` that returns the result of ``sol::as_table``.
This marker does NOT apply to :doc:`usertypes<usertype>`.
You can also use this to nest types and retrieve tables within tables as shown by this example.
.. literalinclude:: ../../../examples/source/containers_as_table.cpp
:linenos:
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