This command removes an argument or the return type from a function prototype. It can be applied to the prototype of the current function as well as to any called function.
It is available only when the cursor is on a function argument or on the return type. As a result of this command, the function prototype is modified: the selected argument is removed from the argument list. If necessary, the calling convention is replaced by a new one.
Please note that other register arguments do not change their locations. This logic ensures that a stray argument in the argument list can be deleted with a keypress.
When applied to the function return type it will convert it to "void".
This command is available starting from v7.5.