import std;

int test(int a = 0) { return a; }

alias cached = memoize!test;

void main()
{ 
    cached(0); // Works;
    cached(1); // Works;
    cached();  // Error
}


Error: function std.functional.memoize!(test).memoize(int _param_0) is not callable using argument types ()
onlineapp.d(11):        missing argument for parameter #1: int _param_0