newbie confusion with arrays and structs

[Jesse Phillips]

The important mangled message here is:

prd.o:(.data+0x250): undefined reference to 
`_D5Array12__ModuleInfoZ'

This is a linker error, your code compiled fine. The English 
translation:

"There is an undefined reference to module Array"

You are compiling without including all files you need

dmd prd.d Array.d -unittest

That should at least get you to the next error. Also name your 
modules with lowercase, this isn't required but is a suggestion.