From 75d69bf9df56912b9fcfb134741d714ba4e2fa5a Mon Sep 17 00:00:00 2001
From: Danny Robson <danny@nerdcruft.net>
Date: Thu, 5 Feb 2015 20:30:45 +1100
Subject: [PATCH] maths: fix the ordering of limit

---
 maths.cpp |  2 ++
 maths.hpp | 10 +++++++++-
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/maths.cpp b/maths.cpp
index b33c64c7..9e89ff88 100644
--- a/maths.cpp
+++ b/maths.cpp
@@ -182,5 +182,7 @@ template int sign (int);
 // so it's easier to instantiate early and check for broken code at library
 // build time.
 
+template float limit (float, float, float);
+
 template float smoothstep (float, float, float);
 template double smoothstep (double, double, double);
diff --git a/maths.hpp b/maths.hpp
index a7c5b756..d5f54b1c 100644
--- a/maths.hpp
+++ b/maths.hpp
@@ -276,10 +276,18 @@ max [[gnu::pure]] (const T a, const U b, Args ...args)
 
 
 //-----------------------------------------------------------------------------
+// Limiting functions
+
+// min/max clamping
 template <typename T, typename U, typename V>
 T
-limit [[gnu::pure]] (const T val, const U hi, const V lo)
+limit [[gnu::pure]] (const T val, const U lo, const V hi)
 {
+    CHECK_LE(
+        decltype (lo+hi) (lo),
+        decltype (hi+lo) (hi)
+    );
+
     return val > hi ? hi:
            val < lo ? lo:
            val;