# Modifying Functions

## modify-argument

> Function modifications consist of a list of `modify-argument` nodes contained in a modify-function node. Use the remove-argument, replace-default-expression, remove-default-expression, replace-type, reference-count and define-ownership nodes to specify the details of the modification.

>     <modify-function>
>         <modify-argument index="return | this | 1 ..." rename="..."
>          invalidate-after-use = "true | false">
>             // modifications
>         </modify-argument>
>     </modify-function>

> Set the `index` attribute to “1” for the first argument, “2” for the second one and so on. Alternatively, set it to “return” or “this” if you want to modify the function’s return value or the object the function is called upon, respectively.

> The optional `rename` attribute is used to rename a argument and use this new name in the generated code.

> For the optional `invalidate-after-use` attribute, see Invalidation after use .