From d0fc14b8c5c20e05d86e52873fb9adbc36341a3f Mon Sep 17 00:00:00 2001
From: Peter Dimov <pdimov@gmail.com>
Date: Sun, 30 Oct 2022 13:40:20 +0200
Subject: [PATCH] Remove C++11 constructs from hash_traits.hpp

---
 include/boost/unordered/hash_traits.hpp | 15 ++++++++-------
 test/Jamfile.v2                         |  2 +-
 2 files changed, 9 insertions(+), 8 deletions(-)

diff --git a/include/boost/unordered/hash_traits.hpp b/include/boost/unordered/hash_traits.hpp
index 5ab4a556..dfc2716f 100644
--- a/include/boost/unordered/hash_traits.hpp
+++ b/include/boost/unordered/hash_traits.hpp
@@ -12,7 +12,7 @@
 #define BOOST_UNORDERED_HASH_TRAITS_HPP
 
 #include <boost/type_traits/make_void.hpp>
-#include <type_traits>
+#include <boost/type_traits/integral_constant.hpp>
 
 namespace boost{
 namespace unordered{
@@ -20,11 +20,12 @@ namespace unordered{
 namespace detail{
 
 template<typename Hash,typename=void>
-struct hash_is_avalanching_impl:std::false_type{};
+struct hash_is_avalanching_impl: boost::false_type{};
 
 template<typename Hash>
-struct hash_is_avalanching_impl<Hash,void_t<typename Hash::is_avalanching>>:
-  std::true_type{};
+struct hash_is_avalanching_impl<Hash,
+  typename boost::make_void<typename Hash::is_avalanching>::type>:
+    boost::true_type{};
 
 } /* namespace detail */
 
@@ -32,11 +33,11 @@ struct hash_is_avalanching_impl<Hash,void_t<typename Hash::is_avalanching>>:
  * when actual characterization differs from default.
  */
 
-/* Derived from std::true_type if the type Hash::is_avalanching is present,
- * derived from std::false_type otherwise.
+/* hash_is_avalanching<Hash>::value is true when the type Hash::is_avalanching
+ * is present, false otherwise.
  */
 template<typename Hash>
-struct hash_is_avalanching:detail::hash_is_avalanching_impl<Hash>::type{};
+struct hash_is_avalanching: detail::hash_is_avalanching_impl<Hash>::type{};
 
 } /* namespace unordered */
 } /* namespace boost */
diff --git a/test/Jamfile.v2 b/test/Jamfile.v2
index 3824b831..6a9d4684 100644
--- a/test/Jamfile.v2
+++ b/test/Jamfile.v2
@@ -139,7 +139,7 @@ build_foa erase_if ;
 build_foa scary_tests ;
 build_foa init_type_insert_tests ;
 
-run unordered/hash_is_avalanching_test.cpp : : : $(CPP11) ;
+run unordered/hash_is_avalanching_test.cpp ;
 
 run exception/constructor_exception_tests.cpp : : : $(CPP11) <define>BOOST_UNORDERED_FOA_TESTS : foa_constructor_exception_tests ;
 run exception/copy_exception_tests.cpp        : : : $(CPP11) <define>BOOST_UNORDERED_FOA_TESTS : foa_copy_exception_tests ;