From e1b7c4726edcef250e1ff84579f90ba97e8941f7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mael=20Rouxel-Labb=C3=A9?=
 <mael.rouxel.labbe@geometryfactory.com>
Date: Thu, 16 Jan 2025 13:40:48 +0100
Subject: [PATCH 1/2] Replace boost::optional with std::optional

See https://github.com/CGAL/cgal/pull/7526
---
 .../internal/peel_slivers.h                     | 12 +++++++-----
 .../CGAL/Triangulation_segment_traverser_3.h    | 17 +++++++++--------
 2 files changed, 16 insertions(+), 13 deletions(-)

diff --git a/Tetrahedral_remeshing/include/CGAL/Tetrahedral_remeshing/internal/peel_slivers.h b/Tetrahedral_remeshing/include/CGAL/Tetrahedral_remeshing/internal/peel_slivers.h
index a4ae96383cd..cbd7d528719 100644
--- a/Tetrahedral_remeshing/include/CGAL/Tetrahedral_remeshing/internal/peel_slivers.h
+++ b/Tetrahedral_remeshing/include/CGAL/Tetrahedral_remeshing/internal/peel_slivers.h
@@ -18,6 +18,8 @@
 #include <CGAL/Tetrahedral_remeshing/internal/tetrahedral_remeshing_helpers.h>
 #include <CGAL/Tetrahedral_remeshing/internal/property_maps.h>
 
+#include <optional>
+
 namespace CGAL
 {
 namespace Tetrahedral_remeshing
@@ -70,16 +72,16 @@ std::size_t peel_slivers(C3T3& c3t3,
     Cell_handle c = c_i.first;
     const std::array<bool, 4>& f_on_surface = c_i.second;
 
-    boost::optional<Surface_patch_index> patch;
+    std::optional<Surface_patch_index> patch;
     for (int i = 0; i < 4; ++i)
     {
       if (f_on_surface[i])
       {
         Surface_patch_index spi = c3t3.surface_patch_index(c, i);
-        if (patch != boost::none && patch.get() != spi)
+        if (patch.has_value() && patch.value() != spi)
         {
           //there are 2 different patches
-          patch = boost::none;
+          patch = std::nullopt;
           break;
         }
         else
@@ -88,7 +90,7 @@ std::size_t peel_slivers(C3T3& c3t3,
         }
       }
     }
-    if (patch == boost::none)
+    if (!patch.has_value())
       continue;
 
     for (int i = 0; i < 4; ++i)
@@ -96,7 +98,7 @@ std::size_t peel_slivers(C3T3& c3t3,
       if (f_on_surface[i])
         c3t3.remove_from_complex(c, i);
       else
-        c3t3.add_to_complex(c, i, patch.get());
+        c3t3.add_to_complex(c, i, patch.value());
     }
 
     c3t3.remove_from_complex(c);
diff --git a/Triangulation_3/include/CGAL/Triangulation_segment_traverser_3.h b/Triangulation_3/include/CGAL/Triangulation_segment_traverser_3.h
index 6f25e793fda..d52f68c5646 100644
--- a/Triangulation_3/include/CGAL/Triangulation_segment_traverser_3.h
+++ b/Triangulation_3/include/CGAL/Triangulation_segment_traverser_3.h
@@ -26,7 +26,7 @@
 #include <CGAL/Triangulation_vertex_base_3.h>
 #include <CGAL/Triangulation_simplex_3.h>
 
-#include <boost/optional.hpp>
+#include <optional>
 
 // If defined, type casting is done statically,
 // reducing type-safety overhead.
@@ -789,8 +789,8 @@ class Triangulation_segment_simplex_iterator_3
           }
         } else {
           auto facet_opt = shared_facet(get_edge(), e_prev);
-          if(static_cast<bool>(facet_opt)) {
-            _curr_simplex = *facet_opt;
+          if(facet_opt.has_value()) {
+            _curr_simplex = facet_opt.value();
           }
           else {
             _curr_simplex = shared_cell(get_edge(), e_prev);
@@ -1002,7 +1002,7 @@ class Triangulation_segment_simplex_iterator_3
     return f1 == f2 || triangulation().mirror_facet(f1) == f2;
   }
 
-  boost::optional<Vertex_handle> shared_vertex(const Edge& e1, const Edge& e2) const
+  std::optional<Vertex_handle> shared_vertex(const Edge& e1, const Edge& e2) const
   {
     Vertex_handle v1a = e1.first->vertex(e1.second);
     Vertex_handle v1b = e1.first->vertex(e1.third);
@@ -1017,14 +1017,15 @@ class Triangulation_segment_simplex_iterator_3
       return {};
   }
 
-  boost::optional<Facet> shared_facet(const Edge& e1, const Edge& e2) const
+  std::optional<Facet> shared_facet(const Edge& e1, const Edge& e2) const
   {
     Vertex_handle v2a = e2.first->vertex(e2.second);
     Vertex_handle v2b = e2.first->vertex(e2.third);
 
     auto sv_opt = shared_vertex(e1, e2);
-    if(!sv_opt) return {};
-    Vertex_handle sv = *sv_opt;
+    if(!sv_opt.has_value())
+      return {};
+    Vertex_handle sv = sv_opt.value();
     Vertex_handle nsv2 = (sv == v2a) ? v2b : v2a;
 
     typename Tr::Facet_circulator circ
@@ -1091,7 +1092,7 @@ class Triangulation_segment_simplex_iterator_3
   }
 
   Cell_handle shared_cell(const Edge e1, const Edge e2) const {
-    auto facet = shared_facet(e1, e2.first->vertex(e2.second));
+    Facet facet = shared_facet(e1, e2.first->vertex(e2.second));
     return shared_cell(facet, e2.first->vertex(e2.third));
   }
 

From 72520db3a86ac7a76454e1b517249636127100c0 Mon Sep 17 00:00:00 2001
From: Mael <mael.rouxel.labbe@geometryfactory.com>
Date: Fri, 17 Jan 2025 09:15:36 +0100
Subject: [PATCH 2/2] Use std::optional::reset

Co-authored-by: Anirudh Lakhanpal <91114837+SharonIV0x86@users.noreply.github.com>
---
 .../include/CGAL/Tetrahedral_remeshing/internal/peel_slivers.h  | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Tetrahedral_remeshing/include/CGAL/Tetrahedral_remeshing/internal/peel_slivers.h b/Tetrahedral_remeshing/include/CGAL/Tetrahedral_remeshing/internal/peel_slivers.h
index cbd7d528719..00d0e16f0a1 100644
--- a/Tetrahedral_remeshing/include/CGAL/Tetrahedral_remeshing/internal/peel_slivers.h
+++ b/Tetrahedral_remeshing/include/CGAL/Tetrahedral_remeshing/internal/peel_slivers.h
@@ -81,7 +81,7 @@ std::size_t peel_slivers(C3T3& c3t3,
         if (patch.has_value() && patch.value() != spi)
         {
           //there are 2 different patches
-          patch = std::nullopt;
+          patch.reset();
           break;
         }
         else