From b1465645adc0ac9b420d7fc5952b3b54b1f4dc08 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20Loriot?= <sebastien.loriot@cgal.org>
Date: Thu, 29 Jun 2023 18:48:15 +0200
Subject: [PATCH] fix variant output

---
 Stream_support/include/CGAL/IO/io.h | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/Stream_support/include/CGAL/IO/io.h b/Stream_support/include/CGAL/IO/io.h
index 3460398bea9..6a5fa185e6b 100644
--- a/Stream_support/include/CGAL/IO/io.h
+++ b/Stream_support/include/CGAL/IO/io.h
@@ -191,13 +191,15 @@ public:
 template <class T, class F>
 class Output_rep<std::optional<T>, F>
 {
-   const std::optional<T>& t;
+  const std::optional<T>& t;
 
 public:
   Output_rep( const std::optional<T>& tt) : t(tt) {}
-  std::ostream& operator()( std::ostream& os) const {
+  std::ostream& operator()( std::ostream& os) const
+  {
     if (t==std::nullopt) return (os << "--");
-    return (os << t.value()); }
+    return (os << t.value());
+  }
 };
 
 template <class ... T, class F>
@@ -207,8 +209,10 @@ class Output_rep<std::variant<T...>, F>
 
 public:
   Output_rep( const std::variant<T...>& tt) : t(tt) {}
-  std::ostream& operator()( std::ostream& os) const {
-    return (os << "--");
+  std::ostream& operator()( std::ostream& os) const
+  {
+    std::visit([&os](auto&& v) { os << v; }, t);
+    return os;
   }
 };