disable span<T, dynamic_extent>::_as_bytes() for MSVC

Author: bernhardmgruber

Vc/common/span.h

@@ -518,6 +518,11 @@ template <typename T> class span<T, dynamic_extent>
     }
 
 #ifdef __cpp_lib_byte
+// Disable _as_bytes() for MSVC as it leads to a compilation error due to a compiler bug.
+// When parsing the return type, MSVC will instantiate the primary template of span<> and static_assert().
+// A bugreport has been submitted and the issue is supposedly fixed in VS 16.10. If so, we can replace the #ifndef by:
+// #if _MSC_VER > 1928
+#ifndef _MSC_VER
     span<const std::byte, dynamic_extent> _as_bytes() const noexcept
     {
         return {reinterpret_cast<const std::byte*>(data()), size_bytes()};
@@ -527,6 +532,7 @@ template <typename T> class span<T, dynamic_extent>
     {
         return {reinterpret_cast<std::byte*>(data()), size_bytes()};
     }
+#endif
 #endif  // __cpp_lib_byte
 
 private: