From 2e476304ede1bdf582a7c09b1e01f70fb80ee226 Mon Sep 17 00:00:00 2001
From: Laurent Rineau <laurent.rineau@cgal.org>
Date: Wed, 10 Nov 2021 09:28:05 +0100
Subject: [PATCH] Fix warnings

> CGAL/Voronoi_diagram_2/Connected_components.h:103:19: warning: ISO C++20 considers use of overloaded operator '!=' (with operand types 'CGAL::VoronoiDiagram_2::Internal::Connected_components<...>::HAVC') to be ambiguous despite there being a unique best viable function with non-reversed arguments [-Wambiguous-reversed-operator]

I changed `operator==` into friend functions.
---
 .../CGAL/Voronoi_diagram_2/Circulator_adaptors.h     |  8 ++++----
 .../CGAL/Voronoi_diagram_2/Iterator_adaptors.h       | 12 ++++++------
 2 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/Voronoi_diagram_2/include/CGAL/Voronoi_diagram_2/Circulator_adaptors.h b/Voronoi_diagram_2/include/CGAL/Voronoi_diagram_2/Circulator_adaptors.h
index b14991c03f3..6b2c567866b 100644
--- a/Voronoi_diagram_2/include/CGAL/Voronoi_diagram_2/Circulator_adaptors.h
+++ b/Voronoi_diagram_2/include/CGAL/Voronoi_diagram_2/Circulator_adaptors.h
@@ -71,13 +71,13 @@ class Circulator_from_halfedge_adaptor
   typename Base::pointer   operator->() { return &cur_; }
   typename Base::reference operator*() { return cur_; }
 
-  bool operator==(const Circulator& other) const {
-    return cur_ == other.cur_;
+  friend bool operator==(const Circulator& c, const Circulator& other) {
+    return c.cur_ == other.cur_;
 
   }
 
-  bool operator!=(const Circulator& other) const {
-    return cur_ != other.cur_;
+  friend bool operator!=(const Circulator& c, const Circulator& other) {
+    return c.cur_ != other.cur_;
   }
 
  protected:
diff --git a/Voronoi_diagram_2/include/CGAL/Voronoi_diagram_2/Iterator_adaptors.h b/Voronoi_diagram_2/include/CGAL/Voronoi_diagram_2/Iterator_adaptors.h
index d88aae38e88..7efc4d6429f 100644
--- a/Voronoi_diagram_2/include/CGAL/Voronoi_diagram_2/Iterator_adaptors.h
+++ b/Voronoi_diagram_2/include/CGAL/Voronoi_diagram_2/Iterator_adaptors.h
@@ -85,13 +85,13 @@ class Iterator_adaptor_base
     return tmp;
   }
 
-  bool operator==(const Iterator& other) const {
+  bool operator==(const Self& other) const {
     if ( vda_ == nullptr ) { return other.vda_ == nullptr; }
     if ( other.vda_ == nullptr ) { return vda_ == nullptr; }
     return ( vda_ == other.vda_ && cur_ == other.cur_ );
   }
 
-  bool operator!=(const Iterator& other) const {
+  bool operator!=(const Self& other) const {
     return !(*this == other);
   }
 
@@ -235,12 +235,12 @@ private:
     return *this;
   }
 
-  bool operator==(const Self& other) const {
-    return Base::operator==(other) && is_first_ == other.is_first_;
+  friend bool operator==(const Self& i, const Self& other) {
+    return i.Base::operator==(other) && i.is_first_ == other.is_first_;
   }
 
-  bool operator!=(const Self& other) const {
-    return !(*this == other);
+  friend bool operator!=(const Self& i, const Self& other) {
+    return !(i == other);
   }
 
  private: