common/bl: fix FTBFS on C++11 due to C++17's if-with-initializer

Fixes: https://tracker.ceph.com/issues/55233
Signed-off-by: Radosław Zarzyński <rzarzyns@redhat.com>
(cherry picked from commit 2528f9d07017cf7cc77f4c02a993d97074db0596)

diff --git a/src/include/buffer.h b/src/include/buffer.h
index 0c89367dd3b2c42fc55bee06981a0bb0e0691886..1b208906db0b726bc7001de7cb1f02439f8a8f2f 100644 (file)
--- a/src/include/buffer.h
+++ b/src/include/buffer.h
@@ -863,7 +863,9 @@ struct error_code;
        if (first_round) {
          impl_f(first_round);
        }
-       if (const auto second_round = len - first_round; second_round) {
+       // no C++17 for the sake of the C++11 guarantees of librados, sorry.
+       const auto second_round = len - first_round;
+       if (second_round) {
          _refill(second_round);
          impl_f(second_round);
        }