'Undefined reference' linking errors

[Ali Çehreli]

Ali Çehreli wrote:

 > D has "reference types". When you pass a class object to a function
 > "by-value", it is actually passed-by-reference.

Didn't mean to leave out the others. These are the "reference"s in D:

- foreach ref parameters

- ref function parameters

- dynamic arrays

- associative arrays

- pointers

I am not sure about function and delegate, and I don't know whether 
there is more that I am missing.

Ali