From fcc02c6bedb0c81e28a3c9c0efc22b7204e87276 Mon Sep 17 00:00:00 2001
From: Pavel Emelyanov <xemul@scylladb.com>
Date: Fri, 3 Sep 2021 15:11:50 +0300
Subject: [PATCH] range_tombstone(_list): Mark some bits noexcept

The range_tombstone's .empty() and .operator bool are trivially such.

The swap()'s noexceptness comes from what it calls -- the without-link
move constructor (noexcept) and .move_assign(). The latter is noexcept
because it's already called from noexcept move-assign operator and
because it calls noexcept move operators of tombstones' fields. The
update_node() is noexcept for the same reason.

The range_tombstone_list's clear() is noexcept because both -- set
clear and disposer lambda are both such.

Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
---
 range_tombstone.hh      | 10 +++++-----
 range_tombstone_list.hh |  2 +-
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/range_tombstone.hh b/range_tombstone.hh
index b1a77ae506..1eff10da32 100644
--- a/range_tombstone.hh
+++ b/range_tombstone.hh
@@ -97,10 +97,10 @@ public:
     // Range tombstone covers all rows with positions p such that: position() <= p < end_position()
     position_in_partition_view position() const;
     position_in_partition_view end_position() const;
-    bool empty() const {
+    bool empty() const noexcept {
         return !bool(tomb);
     }
-    explicit operator bool() const {
+    explicit operator bool() const noexcept {
         return bool(tomb);
     }
     bool equal(const schema& s, const range_tombstone& other) const {
@@ -113,7 +113,7 @@ public:
             return _c(rt1.start_bound(), rt2.start_bound());
         }
     };
-    friend void swap(range_tombstone& rt1, range_tombstone& rt2) {
+    friend void swap(range_tombstone& rt1, range_tombstone& rt2) noexcept {
         range_tombstone tmp(std::move(rt2), without_link());
         rt2.move_assign(std::move(rt1));
         rt1.move_assign(std::move(tmp));
@@ -215,14 +215,14 @@ public:
         return sizeof(range_tombstone) + minimal_external_memory_usage(s);
     }
 private:
-    void move_assign(range_tombstone&& rt) {
+    void move_assign(range_tombstone&& rt) noexcept {
         start = std::move(rt.start);
         start_kind = rt.start_kind;
         end = std::move(rt.end);
         end_kind = rt.end_kind;
         tomb = std::move(rt.tomb);
     }
-    void update_node(bi::set_member_hook<bi::link_mode<bi::auto_unlink>>& other_link) {
+    void update_node(bi::set_member_hook<bi::link_mode<bi::auto_unlink>>& other_link) noexcept {
         if (other_link.is_linked()) {
             // Move the link in case we're being relocated by LSA.
             container_type::node_algorithms::replace_node(other_link.this_ptr(), _link.this_ptr());
diff --git a/range_tombstone_list.hh b/range_tombstone_list.hh
index 24ec35e9e3..638c148de1 100644
--- a/range_tombstone_list.hh
+++ b/range_tombstone_list.hh
@@ -198,7 +198,7 @@ public:
             }
         }
     }
-    void clear() {
+    void clear() noexcept {
         _tombstones.clear_and_dispose(current_deleter<range_tombstone>());
     }