Type classes with type parameters don't work very well

type
  TVecT*[T] = array[0..1, T]|array[0..2, T]|array[0..3, T]
  TVec2* = array[0..1, float32]

proc f[T](a: TVecT[T], b: TVecT[T]): T = discard

#f([0.0'f32, 0.0'f32], [0.0'f32, 0.0'f32])
#f(TVec2([0.0'f32, 0.0'f32]), TVec2([0.0'f32, 0.0'f32]))

Uncommenting the first call to 'f' results in this:

type_param_bug.nim(7, 2) Error: type mismatch: got (Array constructor[0..1, float32], Array constructor[0..1, float32])
**but expected one of: **
type_param_bug.f(a: TVecT[T], b: TVecT[T]): T

and the second call (which isn't valid code) gives me an ICE:

Error: internal error: wrong instantiated type!
Traceback (most recent call last)
nimrod.nim(79) nimrod
nimrod.nim(55) HandleCmdLine
main.nim(487) MainCommand
main.nim(256) CommandCompileToC
main.nim(210) CompileProject
main.nim(168) compileModule
passes.nim(192) processModule
passes.nim(136) processTopLevelStmt
sem.nim(300) myProcess
sem.nim(274) SemStmtAndGenerateGenerics
semstmts.nim(1238) semStmt
semexprs.nim(777) semExprNoType
semexprs.nim(1841) semExpr
semexprs.nim(720) semDirectOp
semexprs.nim(619) semOverloadedCallAnalyseEffects
semcall.nim(156) semOverloadedCall
semcall.nim(66) resolveOverloads
sigmatch.nim(1026) matches
sigmatch.nim(995) matchesAux
sigmatch.nim(816) ParamTypesMatch
sigmatch.nim(746) ParamTypesMatchAux
sigmatch.nim(607) typeRel
msgs.nim(786) InternalError
msgs.nim(724) rawMessage
msgs.nim(721) rawMessage
msgs.nim(674) handleError

[BitPuffin]

Any progress on this? It's ruining linagl :P

[Varriount]

What, specifically, needs work? Any tests that you could submit?