From 1a80896934581d3af85c87d146ca89a776c0ca3a Mon Sep 17 00:00:00 2001
From: Andrey Semashev <andrey.semashev@gmail.com>
Date: Fri, 1 Jul 2022 00:13:32 +0300
Subject: [PATCH] Disabled assignment of output_proxy to output_proxy.

---
 .../iterator/function_output_iterator.hpp     | 21 ++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)

diff --git a/include/boost/iterator/function_output_iterator.hpp b/include/boost/iterator/function_output_iterator.hpp
index 2708bbd..72a864d 100644
--- a/include/boost/iterator/function_output_iterator.hpp
+++ b/include/boost/iterator/function_output_iterator.hpp
@@ -13,6 +13,10 @@
 
 #include <iterator>
 #include <boost/config.hpp>
+#include <boost/core/enable_if.hpp>
+#include <boost/type_traits/is_same.hpp>
+#include <boost/type_traits/remove_cv.hpp>
+#include <boost/type_traits/remove_reference.hpp>
 
 namespace boost {
 namespace iterators {
@@ -24,20 +28,31 @@ namespace iterators {
 
     class output_proxy {
     public:
-      explicit output_proxy(UnaryFunction& f) : m_f(f) { }
+      explicit output_proxy(UnaryFunction& f) BOOST_NOEXCEPT : m_f(f) { }
 
 #ifdef BOOST_NO_CXX11_RVALUE_REFERENCES
-      template <class T> output_proxy& operator=(const T& value) {
+      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) {
         m_f(value);
         return *this;
       }
 #else
-      template <class T> output_proxy& operator=(T&& value) {
+      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) {
         m_f(static_cast< T&& >(value));
         return *this;
       }
 #endif
 
+      BOOST_DEFAULTED_FUNCTION(output_proxy(output_proxy const& that), BOOST_NOEXCEPT : m_f(that.m_f) {})
+      BOOST_DELETED_FUNCTION(output_proxy& operator=(output_proxy const&))
+
     private:
       UnaryFunction& m_f;
     };