How use Predicate (alias pred = "a*b")?

[Marcone]

On Thursday, 13 May 2021 at 21:38:25 UTC, Adam D. Ruppe wrote:
> On Thursday, 13 May 2021 at 21:30:43 UTC, Marcone wrote:
>> template foo(alias pred = "a*b"){
>> 	void foo(int x, int y){
>> 		writeln(x.unaryFun!pred);
>
> First, you really shouldn't use these at all. instead of a 
> string, just pass an actual function to the thing as the 
> predicate.
>
> but if you must use it, unaryFun has one argument, so just a. 
> if you want a and b, two arguments, that's binaryFun.

Thank you. binaryFun solved the problem.