From c89c45877c34e51990e9fb4fa2a768805f12d868 Mon Sep 17 00:00:00 2001
From: Marc Emmers <m.emmers@syrinx.nl>
Date: Mon, 9 Nov 2020 12:56:51 +0100
Subject: [PATCH] Prevent warning on subspan<0,N>

---
 platform/cxxsupport/mstd_span | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/platform/cxxsupport/mstd_span b/platform/cxxsupport/mstd_span
index 79dd22d8cf..282d3474a3 100644
--- a/platform/cxxsupport/mstd_span
+++ b/platform/cxxsupport/mstd_span
@@ -219,7 +219,9 @@ public:
         : (Extent != dynamic_extent ? Extent - Offset : dynamic_extent)> subspan() const
     {
         static_assert(Offset <= extent && (Count == dynamic_extent || Count <= extent - Offset));
-        MBED_ASSERT(Offset <= size() && (Count == dynamic_extent || Count <= size() - Offset));
+        // Only check against Offset == 0 to prevent a warning for subspan<0, N>
+        MBED_ASSERT((Offset == 0 || Offset <= size())
+                    && (Count == dynamic_extent || Count <= size() - Offset));
         return {data() + Offset, Count != dynamic_extent ? Count : size() - Offset};
     }