From 2b25cb131c20a8e3a25ef6646ab3bc3674e23e53 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mael=20Rouxel-Labb=C3=A9?=
 <mael.rouxel.labbe@geometryfactory.com>
Date: Mon, 10 Jan 2022 15:40:04 +0100
Subject: [PATCH] Fix forward declaration living in the wrong namespace

cherry-pick of cd9200091d62e0943fb5638c7f716bfe79bb1947
---
 Bounding_volumes/test/Bounding_volumes/min_sphere_test.cpp | 6 ++++--
 Number_types/include/CGAL/NT_converter.h                   | 5 ++---
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/Bounding_volumes/test/Bounding_volumes/min_sphere_test.cpp b/Bounding_volumes/test/Bounding_volumes/min_sphere_test.cpp
index 82b71269443..ff82ea1bdb0 100644
--- a/Bounding_volumes/test/Bounding_volumes/min_sphere_test.cpp
+++ b/Bounding_volumes/test/Bounding_volumes/min_sphere_test.cpp
@@ -33,10 +33,12 @@
 #include <CGAL/Random.h>
 #include <CGAL/Cartesian_d.h>
 #include <CGAL/Homogeneous_d.h>
-#include <sstream>
-#include <cassert>
 #include <CGAL/Min_sphere_annulus_d_traits_d.h>
 #include <CGAL/Min_sphere_d.h>
+#include <CGAL/Quotient.h>
+
+#include <cassert>
+#include <sstream>
 
 using namespace CGAL;
 
diff --git a/Number_types/include/CGAL/NT_converter.h b/Number_types/include/CGAL/NT_converter.h
index ac225f1e0cb..4a12c4254b1 100644
--- a/Number_types/include/CGAL/NT_converter.h
+++ b/Number_types/include/CGAL/NT_converter.h
@@ -17,11 +17,10 @@
 #include <CGAL/number_type_config.h>
 #include <CGAL/number_utils.h>
 
-template <bool> class Interval_nt;
-
 namespace CGAL {
 
-// A number type converter usable as default, using the conversion operator.
+template <bool>
+class Interval_nt;
 
 template < class NT1, class NT2 >
 struct NT_converter