From 6bbd6cbda38e4345425bbfca2be1e3bc2069c8f9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ignacy=20Gaw=C4=99dzki?=
 <ignacy.gawedzki@green-communications.fr>
Date: Wed, 24 Jul 2024 15:18:29 +0200
Subject: [PATCH] Fix mutant_relation::operator=.
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Defining

  template <bool FM>
  mutant_relation& operator=(const mutant_relation<TA, TB, Info, FM>& rel) {
    base_::change_to(rel);
    return *this;
  }

does not prevent the compiler from implicitly providing

  mutant_relation& operator=(const mutant_relation&);

and hence the implicit version takes over when FM == force_mutable and
does not call base_::change_to.

Replace the template version with two non-template overloads, both
calling base_::change_to.

Signed-off-by: Ignacy Gawędzki <ignacy.gawedzki@green-communications.fr>
---
 include/boost/bimap/relation/mutant_relation.hpp | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/include/boost/bimap/relation/mutant_relation.hpp b/include/boost/bimap/relation/mutant_relation.hpp
index 1681a9d0..eda9a8c9 100644
--- a/include/boost/bimap/relation/mutant_relation.hpp
+++ b/include/boost/bimap/relation/mutant_relation.hpp
@@ -289,8 +289,14 @@ class mutant_relation : public
 
     // Operators
 
-    template< bool FM >
-    mutant_relation& operator=(const mutant_relation<TA,TB,Info,FM> & rel)
+    mutant_relation& operator=(const mutant_relation & rel)
+    {
+        base_::change_to(rel);
+        return *this;
+    }
+
+    mutant_relation& operator=(const mutant_relation<TA,TB,Info,
+                                                     !force_mutable> & rel)
     {
         base_::change_to(rel);
         return *this;