From abd465621779bb5bef3cf3eed7175151c8d6e263 Mon Sep 17 00:00:00 2001
From: David Wells <drwells@email.unc.edu>
Date: Tue, 4 Jan 2022 12:46:30 -0500
Subject: [PATCH] Fix compilation with boost 1.78.

I bisected (fortunately Boost.Geometry a header-only library so adding the
include directory sufficed) and
https://github.com/boostorg/geometry/commit/6eb9e238bcb37e26dc31d16acf826784a2ba30f4
is where this problem starts for us. See also
https://github.com/boostorg/geometry/issues/792 - the easiest fix for all such
issues is to just include the project header `boost/geometry/geometry.hpp`.

In this particular case, if you look at the commit which causes grid_tools.cc
fails to compile, its because we were relying on some implicit includes. In
particular, we need the distance header to find the distance between points and
boxes, but that was previously included in another file.
---
 include/deal.II/numerics/rtree.h | 2 ++
 tests/boost/rtree_01.cc          | 1 +
 2 files changed, 3 insertions(+)

diff --git a/include/deal.II/numerics/rtree.h b/include/deal.II/numerics/rtree.h
index 68fa11e2e3..a40e242539 100644
--- a/include/deal.II/numerics/rtree.h
+++ b/include/deal.II/numerics/rtree.h
@@ -26,6 +26,8 @@
 #include <deal.II/boost_adaptors/segment.h>
 
 DEAL_II_DISABLE_EXTRA_DIAGNOSTICS
+#include <boost/geometry/algorithms/distance.hpp>
+
 #ifdef DEAL_II_BOOST_HAS_BROKEN_HEADER_DEPRECATIONS
 #  define BOOST_ALLOW_DEPRECATED_HEADERS
 #endif
diff --git a/tests/boost/rtree_01.cc b/tests/boost/rtree_01.cc
index c0a25a50a0..40b2e852b2 100644
--- a/tests/boost/rtree_01.cc
+++ b/tests/boost/rtree_01.cc
@@ -19,6 +19,7 @@
 
 #include <deal.II/boost_adaptors/point.h>
 
+#include <boost/geometry/algorithms/distance.hpp>
 #include <boost/geometry/index/rtree.hpp>
 #include <boost/geometry/strategies/strategies.hpp>
 
-- 
2.39.5