From 0fb4d92d83a054fcbf50c51675e3d9aa7f664bd5 Mon Sep 17 00:00:00 2001
From: Andrey Semashev <andrey.semashev@gmail.com>
Date: Wed, 7 Feb 2024 15:12:36 +0300
Subject: [PATCH] Moved checked deleters into internal namespace to block
 unintended ADL.

This prevents adding namespace boost to ADL when the deleters are used
in template parameters, e.g. in std::unique_ptr.
---
 doc/changes.qbk                               |  6 ++--
 include/boost/core/checked_delete.hpp         |  9 ++++++
 test/Jamfile.v2                               |  4 +++
 ...checked_array_deleter_compile_fail_adl.cpp | 30 +++++++++++++++++++
 test/checked_deleter_compile_fail_adl.cpp     | 30 +++++++++++++++++++
 5 files changed, 76 insertions(+), 3 deletions(-)
 create mode 100644 test/checked_array_deleter_compile_fail_adl.cpp
 create mode 100644 test/checked_deleter_compile_fail_adl.cpp

diff --git a/doc/changes.qbk b/doc/changes.qbk
index ecaeffa..0213c9c 100644
--- a/doc/changes.qbk
+++ b/doc/changes.qbk
@@ -11,9 +11,9 @@
 
 * Added a new [link core.functor `boost/core/functor.hpp`] header with a `functor` class template
   for wrapping a raw function into a function object class.
-* Changed [link core.null_deleter `null_deleter`] and [link core.fclose_deleter `fclose_deleter`]
-  definitions so that they don't bring namespace `boost` into argument-dependent lookup in cases
-  like this:
+* Changed [link core.null_deleter `null_deleter`], [link core.fclose_deleter `fclose_deleter`]
+  and [link.checked_delete checked deleter] definitions so that they don't bring namespace `boost`
+  into argument-dependent lookup in cases like this:
   ```
   std::unique_ptr< std::FILE, boost::fclose_deleter > p1, p2;
   swap(p1, p2); // no longer looks for boost::swap as part of ADL
diff --git a/include/boost/core/checked_delete.hpp b/include/boost/core/checked_delete.hpp
index b74a43a..67f3c74 100644
--- a/include/boost/core/checked_delete.hpp
+++ b/include/boost/core/checked_delete.hpp
@@ -60,6 +60,10 @@ template<class T> inline void checked_array_delete(T * x) BOOST_NOEXCEPT
     delete [] x;
 }
 
+// Block unintended ADL
+namespace checked_deleters
+{
+
 template<class T> struct checked_deleter
 {
     typedef void result_type;
@@ -83,6 +87,11 @@ template<class T> struct checked_array_deleter
     }
 };
 
+} // namespace checked_deleters
+
+using checked_deleters::checked_deleter;
+using checked_deleters::checked_array_deleter;
+
 } // namespace boost
 
 #endif  // #ifndef BOOST_CORE_CHECKED_DELETE_HPP
diff --git a/test/Jamfile.v2 b/test/Jamfile.v2
index 31d740d..2bc6a4b 100644
--- a/test/Jamfile.v2
+++ b/test/Jamfile.v2
@@ -39,6 +39,10 @@ compile-fail checked_delete_fail.cpp
   : $(warnings-as-errors-off) ;
 compile-fail checked_delete_fail2.cpp
   : $(warnings-as-errors-off) ;
+compile-fail checked_deleter_compile_fail_adl.cpp
+  : $(warnings-as-errors-off) ;
+compile-fail checked_array_deleter_compile_fail_adl.cpp
+  : $(warnings-as-errors-off) ;
 
 compile ref_ct_test.cpp ;
 run ref_test.cpp ;
diff --git a/test/checked_array_deleter_compile_fail_adl.cpp b/test/checked_array_deleter_compile_fail_adl.cpp
new file mode 100644
index 0000000..f1db4ba
--- /dev/null
+++ b/test/checked_array_deleter_compile_fail_adl.cpp
@@ -0,0 +1,30 @@
+/*
+ *             Copyright Andrey Semashev 2024.
+ * Distributed under the Boost Software License, Version 1.0.
+ *    (See accompanying file LICENSE_1_0.txt or copy at
+ *          http://www.boost.org/LICENSE_1_0.txt)
+ */
+/*!
+ * \file   checked_array_deleter_compile_fail_adl.cpp
+ * \author Andrey Semashev
+ * \date   07.02.2024
+ *
+ * This file tests that \c boost::checked_array_deleter doesn't bring namespace
+ * \c boost into ADL.
+ */
+
+#include <boost/core/checked_delete.hpp>
+
+namespace boost {
+
+void check_adl(checked_array_deleter< int > const&)
+{
+}
+
+} // namespace boost
+
+int main()
+{
+    // Must not find boost::check_adl
+    check_adl(boost::checked_array_deleter< int >());
+}
diff --git a/test/checked_deleter_compile_fail_adl.cpp b/test/checked_deleter_compile_fail_adl.cpp
new file mode 100644
index 0000000..c736f25
--- /dev/null
+++ b/test/checked_deleter_compile_fail_adl.cpp
@@ -0,0 +1,30 @@
+/*
+ *             Copyright Andrey Semashev 2024.
+ * Distributed under the Boost Software License, Version 1.0.
+ *    (See accompanying file LICENSE_1_0.txt or copy at
+ *          http://www.boost.org/LICENSE_1_0.txt)
+ */
+/*!
+ * \file   checked_deleter_compile_fail_adl.cpp
+ * \author Andrey Semashev
+ * \date   07.02.2024
+ *
+ * This file tests that \c boost::checked_deleter doesn't bring namespace
+ * \c boost into ADL.
+ */
+
+#include <boost/core/checked_delete.hpp>
+
+namespace boost {
+
+void check_adl(checked_deleter< int > const&)
+{
+}
+
+} // namespace boost
+
+int main()
+{
+    // Must not find boost::check_adl
+    check_adl(boost::checked_deleter< int >());
+}