From 8ce2a9f83527cf60adc75a89d6d63ce9933404c5 Mon Sep 17 00:00:00 2001
From: Peter Dimov <pdimov@gmail.com>
Date: Sun, 22 Jan 2023 01:22:02 +0200
Subject: [PATCH] Disable result converting constructor when T is convertible
 from the rhs result<T2, E2>. Refs #104.

---
 include/boost/system/result.hpp | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/include/boost/system/result.hpp b/include/boost/system/result.hpp
index 33eec39..8479b36 100644
--- a/include/boost/system/result.hpp
+++ b/include/boost/system/result.hpp
@@ -187,7 +187,8 @@ public:
     // converting
     template<class T2, class E2, class En = typename std::enable_if<
         std::is_convertible<T2, T>::value &&
-        std::is_convertible<E2, E>::value
+        std::is_convertible<E2, E>::value &&
+        !std::is_convertible<result<T2, E2> const&, T>::value
         >::type>
     BOOST_CXX14_CONSTEXPR result( result<T2, E2> const& r2 )
         noexcept(
@@ -205,7 +206,8 @@ public:
 
     template<class T2, class E2, class En = typename std::enable_if<
         std::is_convertible<T2, T>::value &&
-        std::is_convertible<E2, E>::value
+        std::is_convertible<E2, E>::value &&
+        !std::is_convertible<result<T2, E2>&&, T>::value
         >::type>
     BOOST_CXX14_CONSTEXPR result( result<T2, E2>&& r2 )
         noexcept(