Bump the minimum C++ standard to 20.

debian/changelog

@@ -1,3 +1,9 @@
+lxqt-build-tools (2.1.0-0ubuntu2) UNRELEASED; urgency=medium
+
+  * Bump the minimum C++ standard to 20.
+
+ -- Simon Quigley <tsimonq2@ubuntu.com>  Fri, 03 Jan 2025 01:45:08 -0600
+
 lxqt-build-tools (2.1.0-0ubuntu1) plucky; urgency=medium
 
   * New upstream release.

debian/patches/cpp20.patch

@@ -0,0 +1,26 @@
+Description: Bump the minimum compatibility level to C++20
+ This pull request is very similar to
+ https://github.com/lxqt/lxqt-build-tools/pull/83, except this is proactive
+ rather than reactive.
+Author: Simon Quigley <tsimonq2@ubuntu.com>
+Origin: upstream
+Forwarded: https://github.com/lxqt/lxqt-build-tools/pull/102
+Last-Update: 2025-01-03
+---
+This patch header follows DEP-3: http://dep.debian.net/deps/dep3/
+--- a/cmake/modules/LXQtCompilerSettings.cmake
++++ b/cmake/modules/LXQtCompilerSettings.cmake
+@@ -181,11 +181,11 @@ endif()
+ 
+ 
+ #-----------------------------------------------------------------------------
+-# CXX17 requirements - no checks, we just set it
++# CXX20 requirements - no checks, we just set it
+ #-----------------------------------------------------------------------------
+ set(CMAKE_CXX_STANDARD_REQUIRED True)
+ set(CMAKE_CXX_EXTENSIONS OFF)
+-set(CMAKE_CXX_STANDARD 17 CACHE STRING "C++ ISO Standard")
++set(CMAKE_CXX_STANDARD 20 CACHE STRING "C++ ISO Standard")
+ 
+ 
+ #-----------------------------------------------------------------------------

debian/patches/series

@@ -0,0 +1 @@
+cpp20.patch