nim-wiki/Feature-Matrix.md

Language feature	Scheduled for	Notes
Automatic dereference in more contexts	0.9.6	important to be able to write more generic containers easily
support overloading of the assignment operator	0.9.6	like fields and destructors an assignment operator needs to be lifted
destructors need to interact with finalizers	0.9.6	destructors and finalizers are implemented, but do not interact. new which takes a finalizer needs to be deprecated. People should use a destructor instead
the new concurrency model	0.9.6	this requires frontend and backend changes, but no changes to the runtime/GC
weaken the requirements for forward declarations	after 1.0	two different design ideas exist: one conservative and so will work, the other highly experimental
comment handling is weird	0.9.6	comments should be optional and not part of the grammar, unless it is a documentation comment
push pragma needs to be reworked	after 1.0	it should be distinguished between 'push' for 'type', 'proc' etc.
pragmas are not supported for 'bindSym'	0.9.6	this makes clean macros impossible to write when it comes to pragmas
type checking for tuples	0.9.8	needs to be refined. Recursive tuples should be forbidden.
extended macros API	0.9.8	missing: an API for working with types; the builtin getImpl
write tracking	0.9.8	algorithm exists. Can be extended to compute lent pointers.
prevent object branch transitions from low(selector)	after 1.0	object branch transitions from low(selector) are allowed, because they are simply too useful, but can break memory safety. Now that the language has a proper notion of construction, we can make them safe.
~ operator for effects	after 1.0	it is not entirely clear what ~F should mean.
some effects like GCMem don't need to be white-listed	after 1.0	unclear whether this only affects built-in properties like GCMem, Recursive.
returning 'var T' is unsafe and needs static analysis to make safe	after 1.0	the compiler already checks for trivial examples
alias analysis needs to specified and controllable with pragmas	after 1.0	alias analysis affects memory safety rules
term rewriting macros need more love	after 1.0	we need much more tests and use them in production
Compiler feature	Scheduled for	Notes
high level optimizer	after 1.0	use the effect system for optimizations; interacts with TR macros; performs: GCSE <li>loop invariant hoisting</li> <li>escape analysis for string/seq</li> <li>inlining of small lambdas</li> </ul>
pure RC'ing GC	after 1.0	important for better interoperability with Objective-C
GPU backend	after 1.0
symbol files	after 1.0
deterministic code generation	0.9.8