From 8a6ae0bd379e701cb1646330b95b371aa3ac8613 Mon Sep 17 00:00:00 2001
From: Alec Theriault <alec.theriault@gmail.com>
Date: Wed, 15 Feb 2017 15:59:24 -0800
Subject: [PATCH] Enable 'PolyKinds' in Linear.Trace (#122)

This turns on 'PolyKinds' for appropriate GHC versions in 'Linear.Trace'.
The particular motivation is to generalize the `instance Dim * n =>
Trace (V * n)` to the kind `Nat`, such that `trace m` compiles for types
like `m :: V 5 (V 5 n)`.

Fixes #121
---
 src/Linear/Trace.hs | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/Linear/Trace.hs b/src/Linear/Trace.hs
index 2c7a5c4..005152b 100644
--- a/src/Linear/Trace.hs
+++ b/src/Linear/Trace.hs
@@ -1,6 +1,9 @@
 {-# LANGUAGE CPP #-}
 {-# LANGUAGE TypeOperators #-}
 {-# LANGUAGE DefaultSignatures #-}
+#if __GLASGOW_HASKELL__ >= 707
+{-# LANGUAGE PolyKinds #-}
+#endif
 #if __GLASGOW_HASKELL__ >= 702 && __GLASGOW_HASKELL__ < 710
 {-# LANGUAGE Trustworthy #-}
 #endif