From 8022d459e5f0862841236dc2bba4984a1395687c Mon Sep 17 00:00:00 2001
From: Danny Robson <danny@nerdcruft.net>
Date: Wed, 3 Feb 2016 13:56:40 +1100
Subject: [PATCH] maths: add samesign convenience function

---
 maths.hpp | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/maths.hpp b/maths.hpp
index 5db3d158..fb48a823 100644
--- a/maths.hpp
+++ b/maths.hpp
@@ -292,6 +292,15 @@ namespace util {
         return std::signbit (t) ? -1 : 1;
     }
 
+    //-------------------------------------------------------------------------
+    template <typename T>
+    constexpr
+    bool
+    samesign (T a, T b)
+    {
+        return a < 0 && b < 0 || a > 0 && b > 0;
+    }
+
 
     ///////////////////////////////////////////////////////////////////////////////
     // factorisation