gmqcc/tests/fieldparams.qc

void(string, string) print = #1;
entity() spawn = #3;

.string a;
.string b;

void(entity e, .string s) callout = {
    print(e.s, "\n");
};

void() main = {
    local entity e;
    e = spawn();
    e.a = "foo";
    e.b = "bar";
    callout(e, b);
};