( https://dpaste.dzfl.pl/79301f12e5fc )

// ------ Example: ----------

template A(alias Arg) {
	enum A = Arg;
	enum Unrelated = ({return 0;})(); // Error: expression & asdf is not a valid template value argument
};

void main() {
	enum FnPtr = &asdf;
	enum _ = A!FnPtr;
};

void asdf() {};

// ------------------

remove the "enum Unrelated =" line and it compiles fine.
this also compiles fine: https://dpaste.dzfl.pl/fca15065a4cf