Turn list into arguments for cmake function

So let's say we have a CMake function called func which takes named arguments, say NAMED1 and NAMED2. The first argument is mandatory and the second is optional. For example

func(NAMED1 foo NAMED2 optional) 

Now I have a loop which needs to call this function func at each iteration, but depending on the current iteration I sometimes need to supply the optional value and sometimes not. So at each iteration I build a list of the arguments, say

list(APPEND args "NAMED1" "foo") if (...something...) list(APPEND args "NAMED2" "optional") endif() 

So I have the args list now. As a string, it may look like

NAMED1;foo 

or it may look like

NAMED1;foo;NAMED2;optional 

So I thought to string replace the whole list with

string(REPLACE ";" " " args "${args}") 

Then the resulting args will look like

NAMED1 foo NAMED2 optional 

So I thought to pass this string to the function func, with

func("${args}") 

But the problem now is that CMake thinks this is one big string, while it should interpret it as separate strings. How can I achieve this?