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Diffstat (limited to 'compiler/GHC/Tc/Deriv.hs')
| -rw-r--r-- | compiler/GHC/Tc/Deriv.hs | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/compiler/GHC/Tc/Deriv.hs b/compiler/GHC/Tc/Deriv.hs index 4d072fff5f..7a536fcaf7 100644 --- a/compiler/GHC/Tc/Deriv.hs +++ b/compiler/GHC/Tc/Deriv.hs @@ -723,7 +723,7 @@ tcStandaloneDerivInstType ctxt (HsWC { hswc_body = deriv_ty@(L loc (HsSig { sig_bndrs = outer_bndrs , sig_body = deriv_ty_body }))}) | (theta, rho) <- splitLHsQualTy deriv_ty_body - , L _ [wc_pred] <- theta + , [wc_pred] <- fromMaybeContext theta , L wc_span (HsWildCardTy _) <- ignoreParens wc_pred = do dfun_ty <- tcHsClsInstType ctxt $ L loc $ HsSig { sig_ext = noExtField |