reify does not report the use of PromotedT

C.hs

{-# LANGUAGE DataKinds #-}
{-# LANGUAGE KindSignatures #-}
module C where

class C (a :: Bool)

instance C True
instance C 'False -- ' syntax doesn't make a difference

Main.hs

{-# LANGUAGE DataKinds #-}
{-# LANGUAGE TemplateHaskell #-}
{-# LANGUAGE KindSignatures #-}
module Main where

import C
import Language.Haskell.TH

main = do
  putStrLn "reify uses ConT True" 
  mapM_ putStrLn $(do
        ClassI _ insts <- reify ''C
        listE (map (\ (InstanceD _ hd _) -> stringE (show hd)) insts))

  putStrLn "\noxford brackets use PromotedT"
  putStrLn $([t| C True |] >>= stringE . show)
  
{- runghc Main  with 7.10.2
  
reify uses ConT True
AppT (ConT C.C) (ConT GHC.Types.False)
AppT (ConT C.C) (ConT GHC.Types.True)

oxford brackets use PromotedT
AppT (ConT C.C) (PromotedT GHC.Types.True)
  
  
-}