From aa7426bde6f8f76d57dfd1b43fb087b3a3a24d18 Mon Sep 17 00:00:00 2001
From: Avi Kivity <avi@scylladb.com>
Date: Mon, 21 Sep 2020 14:53:00 +0300
Subject: [PATCH] sstables: index_reader: make 'index_bound' public

index_reader::index_bound must be constructible by non-friend classes
since it's used in std::optional (which isn't anyone's friend). This
now works in gcc because gcc's inter-template access checking is broken,
but clang correctly rejects it.
---
 sstables/index_reader.hh | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/sstables/index_reader.hh b/sstables/index_reader.hh
index 31e2ba2a05..aac8fb3d08 100644
--- a/sstables/index_reader.hh
+++ b/sstables/index_reader.hh
@@ -390,6 +390,10 @@ class index_reader {
         tombstone tomb;
     };
 
+public: // Otherwise std::optional<index_bound>::emplace() fails, since
+        // it has a constraint std::is_constructible_v<T>, which fails with
+        // private types
+
     // Contains information about index_reader position in the index file
     struct index_bound {
         shared_index_lists::list_ptr current_list;
@@ -402,6 +406,7 @@ class index_reader {
         std::optional<open_rt_marker> end_open_marker;
     };
 
+private:
     index_bound _lower_bound;
     // Upper bound may remain uninitialized
     std::optional<index_bound> _upper_bound;