From 7c55a6cef8c15a72dc5cfec6bad9d2b12fbc968f Mon Sep 17 00:00:00 2001
From: Andrey Semashev <andrey.semashev@gmail.com>
Date: Fri, 11 Oct 2024 00:34:28 +0300
Subject: [PATCH] Marked output_proxy assignment as const.

This is also required for compliance with std::output_iterator concept.
---
 include/boost/iterator/function_output_iterator.hpp | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/include/boost/iterator/function_output_iterator.hpp b/include/boost/iterator/function_output_iterator.hpp
index eeb8ddf00..ea2a668bb 100644
--- a/include/boost/iterator/function_output_iterator.hpp
+++ b/include/boost/iterator/function_output_iterator.hpp
@@ -37,8 +37,8 @@ namespace iterators {
       template <class T>
       typename boost::disable_if_c<
         boost::is_same< typename boost::remove_cv< T >::type, output_proxy >::value,
-        output_proxy&
-      >::type operator=(const T& value) {
+        output_proxy const&
+      >::type operator=(const T& value) const {
         m_f(value);
         return *this;
       }
@@ -46,8 +46,8 @@ namespace iterators {
       template <class T>
       typename boost::disable_if_c<
         boost::is_same< typename boost::remove_cv< typename boost::remove_reference< T >::type >::type, output_proxy >::value,
-        output_proxy&
-      >::type operator=(T&& value) {
+        output_proxy const&
+      >::type operator=(T&& value) const {
         m_f(static_cast< T&& >(value));
         return *this;
       }