This code fails with the errors:

    foo.d(5): function call (void(*value)(char[]v)) does not match argument types (v
oid(*)(int v))
    foo.d(5): cannot implicitly convert void(*)(int v) to void(*)(char[]v)

It should compile correctly; the anonymous function in foo.func is not being instantiated for each mixin.  This is the code:

    template foo (type)
    {
        void func ()
        {
            call (function void (type v) { });
        }
    }

    struct tvec (type)
    {
        mixin foo! (type);
        void call (void function (type v) value) { }
    }

    tvec! (int) a;
    tvec! (char []) b;