(unordered)
* keyword: asm
* keyword: in out body
* keyword: cent
* keyword: cdouble
* keyword: cfloat
* keyword: char (test that it realy is unsigned)
* keyword: creal
* keyword: const
* keyword: continue
* keyword: dchar
* keyword: delegate
* keyword: export
* keyword: extern
* keyword: function
* keyword: idouble
* keyword: ifloat
* keyword: import
* keyword: invariant (when: public, export, destructor; circumvention with pointers possible?)
* keyword: ireal
* keyword: module
* keyword: package
* keyword: private
* keyword: protected
* keyword: public
* keyword: struct (anonymous)
* keyword: synchronized
* keyword: ucent
* keyword: unittest
* keyword: volatile
* keyword: wchar

* extend tests for design by contract

* extend tests for inner functions

* operators

* custom operator implementations

* octal and decimal integer literals

* floating literals

* IEEE 754 tests

* module initializers & destructors

* maximum possible size of source/name/arrays/strings

* maximum possible amount of aliases / templates / vars / functions in a source file

* howmany sourcefiles can be compiled in one go?