4 fail_compilation/b19523.d(13): Error: undefined identifier `SomeStruct`
5 fail_compilation/b19523.d(14): Error: function `foo` is not callable using argument types `(_error_)`
6 fail_compilation/b19523.d(14): cannot pass argument `__lambda2` of type `_error_` to parameter `int delegate() arg`
7 fail_compilation/b19523.d(19): `b19523.foo(int delegate() arg)` declared here
19 void foo (int delegate() arg
) {}