doc/dev/encoding.txt: update per std::optional

Signed-off-by: Radoslaw Zarzynski <rzarzyns@redhat.com>
(cherry picked from commit 622829cebcca8ae4ec6f0463a4d74c909998a92d)

diff --git a/doc/dev/network-encoding.rst b/doc/dev/network-encoding.rst
index d59b0ee9ee50beeb57e9e08bd0bd77c28f06ce01..d5d1a6d15371422933f0997c6b0ca48fcdd510fc 100644 (file)
--- a/doc/dev/network-encoding.rst
+++ b/doc/dev/network-encoding.rst
@@ -87,7 +87,8 @@ Optionals are represented as a presence byte, followed by the item if it exists.
                T  element[present? 1 : 0]; // Only if present is non-zero.
        }
 
-Optionals are used to encode ``boost::optional``.
+Optionals are used to encode ``boost::optional`` and, since introducing
+C++17 to Ceph, ``std::optional``.
 
 Pair
 ----