From: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Date: Tue, 12 Mar 2024 19:48:09 +0000 (-0400)
Subject: Build fix: missing operator- for iterator on g++7
X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=commitdiff_plain;h=d83ba9baef029eedf530d272d95487e9c59d4226

Build fix: missing operator- for iterator on g++7

The project fails to build on 'g++ (SUSE Linux) 7.5.0' since its STL
implementation assumes that operator- is available for random access
iterators.

The build fails with the following error:

  event_name.cpp:82:71:   required from here
  /usr/include/c++/7/bits/stl_iterator_base_funcs.h:104:21: error: no match for ‘operator-’ (operand types are ‘lttng::utils::random_access_container_wrapper<const bt_value*, const char*, event_name_set_operations>::_iterator<const lttng::utils::random_access_container_wrapper<const bt_value*, const char*, event_name_set_operations>, const char* const>’ and ‘lttng::utils::random_access_container_wrapper<const bt_value*, const char*, event_name_set_operations>::_iterator<const lttng::utils::random_access_container_wrapper<const bt_value*, const char*, event_name_set_operations>, const char* const>’)

A trivial implementation of that operator is provided and allows the
build to succeed.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ib1637e81e5cdc42cd5a142dcee21150ced9fcc55
---

diff --git a/src/common/container-wrapper.hpp b/src/common/container-wrapper.hpp
index 20642a8d2..25385fc43 100644
--- a/src/common/container-wrapper.hpp
+++ b/src/common/container-wrapper.hpp
@@ -60,6 +60,11 @@ class random_access_container_wrapper {
 			return *this;
 		}
 
+		ptrdiff_t operator-(const _iterator& other) const
+		{
+			return _index - other._index;
+		}
+
 		bool operator==(const _iterator& other) const noexcept
 		{
 			return _index == other._index;