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30 lines
1.4 KiB
ReStructuredText
30 lines
1.4 KiB
ReStructuredText
as_function
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===========
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make sure an object is pushed as a function
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-------------------------------------------
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.. code-block:: cpp
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template <typename Sig = sol::function_sig<>, typename... Args>
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function_argumants<Sig, Args...> as_function ( Args&& ... );
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This function serves the purpose of ensuring that a callable struct (like a lambda) can be passed to the ``set( key, value )`` calls on :ref:`sol::table<set-value>` and be treated like a function binding instead of a userdata. It is recommended that one uses the :ref:`sol::table::set_function<set-function>` call instead, but if for some reason one must use `set`, then `as_function` can help ensure a callable struct is handled like a lambda / callable, and not as just a userdata structure.
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.. code-block:: cpp
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struct callable {
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int operator()( int a, bool b ) {
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return a + b ? 10 : 20;
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}
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};
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sol::state lua;
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// Binds struct as userdata
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lua.set( "not_func", callable() );
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// Binds struct as function
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lua.set( "func", sol::as_function( callable() ) );
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// equivalent: lua.set_function( "func", callable() );
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// equivalent: lua["func"] = callable();
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Note that if you actually want a userdata, but you want it to be callable, you simply need to create a :ref:`sol::table::new_usertype<new-usertype>` and then bind the ``"__call"`` metamethod (or just use ``sol::meta_function::call`` :ref:`enumeration<meta_function_enum>`). |