util/SpanCast: rewrite ToStringView(std::span<std::byte>) to avoid ca…

…st ambiguities

src/util/SpanCast.hxx

@@ -98,3 +98,15 @@ ToStringView(std::span<T> s) noexcept
 {
 	return {s.data(), s.size()};
 }
+
+/* this overload matches std::span<std::byte> (without "const") and is
+   written that way to avoid ambiguities when passing an object that
+   has cast operators for both std::span<std::byte> and
+   std::span<const std::byte> */
+template<typename T>
+constexpr std::string_view
+ToStringView(std::span<T> s) noexcept
+	requires(std::is_same_v<std::remove_const_t<T>, std::byte>)
+{
+	return ToStringView(FromBytesStrict<const char>(s));
+}