Template Haskell silently boxes tuples

Here is a small program:

{-# LANGUAGE TemplateHaskell, UnboxedTuples #-}
module T where

$(id [d| f g x = case g x of (# _, _ #) -> x |])

Output of ghci -ddump-splices:

  f g[aR4] x[aR5] = case g[aR4] x[aR5] of { (_, _) -> x[aR5] }

Note how the tuple has been silently converted to a boxed one. TH shouldn't accept this program since it can't deal with unboxed tuples.

Trac metadata

Trac field	Value
Version	6.10.4
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Template Haskell
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