1 files changed, 5 insertions, 0 deletions
diff --git a/include/o3tl/span.hxx b/include/o3tl/span.hxx
index 8af8ba846b65..087d1f9d69c3 100644
--- a/include/o3tl/span.hxx
+++ b/include/o3tl/span.hxx
@@ -25,6 +25,7 @@ namespace o3tl { using std::span; }
 #include <cassert>
 #include <cstddef>
 #include <iterator>
+#include <type_traits>
 
 namespace o3tl {
 
@@ -57,6 +58,10 @@ public:
         assert(a != nullptr || len == 0);
     }
 
+    /** for assigning from span<T> to span<const T> */
+    constexpr span (const span<typename std::remove_const<T>::type>& other) noexcept
+        : data_(other.data()), size_(other.size()) {}
+
     constexpr bool empty() const noexcept { return size_ == 0; }
 
     constexpr iterator begin() const noexcept { return data_; }