From 5e7771f879b6496dc10f17f94aace3faf70c6f71 Mon Sep 17 00:00:00 2001
From: Neil MacIntosh <neilmac@microsoft.com>
Date: Wed, 20 Jul 2016 09:00:10 -0700
Subject: [PATCH] Slight tidy-up to precondition checking in span.

---
 include/span.h | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/include/span.h b/include/span.h
index fbed6f7..13e57ae 100644
--- a/include/span.h
+++ b/include/span.h
@@ -380,7 +380,7 @@ public:
     {}
 
     constexpr span(pointer ptr, index_type count) : storage_(ptr, count)
-    { Expects((!ptr && count == 0) || (ptr && count >= 0)); }
+    {}
 
     constexpr span(pointer firstElem, pointer lastElem)
         : storage_(firstElem, std::distance(firstElem, lastElem))
@@ -575,7 +575,8 @@ private:
     public:
         template <class OtherExtentType>
         constexpr storage_type(pointer data, OtherExtentType ext)
-            : ExtentType(ext), data_(data) {}
+            : ExtentType(ext), data_(data)
+        { Expects((!data && size() == 0) || (data && size() >= 0)); }
 
         constexpr inline pointer data() const noexcept
         { return data_; }