Support std::error_code and std::error_condition

include/boost/container_hash/hash/hash.hpp

@@ -5,7 +5,7 @@
 
 //  Based on Peter Dimov's proposal
 //  http://www.open-std.org/JTC1/SC22/WG21/docs/papers/2005/n1756.pdf
-//  issue 6.18. 
+//  issue 6.18.
 //
 //  This also contains public domain code from MurmurHash. From the
 //  MurmurHash header:
@@ -34,6 +34,10 @@
 #include <typeindex>
 #endif
 
+#if !defined(BOOST_NO_CXX11_HDR_SYSTEM_ERROR)
+#include <system_error>
+#endif
+
 #if defined(BOOST_MSVC)
 #pragma warning(push)
 
@@ -211,6 +215,11 @@ namespace boost
     std::size_t hash_value(std::type_index);
 #endif
 
+#if !defined(BOOST_NO_CXX11_HDR_SYSTEM_ERROR)
+    std::size_t hash_value(std::error_code const&);
+    std::size_t hash_value(std::error_condition const&);
+#endif
+
     // Implementation
 
     namespace hash_detail
@@ -460,14 +469,30 @@ namespace boost
     }
 #endif
 
+#if !defined(BOOST_NO_CXX11_HDR_SYSTEM_ERROR)
+    inline std::size_t hash_value(std::error_code const& v) {
+        std::size_t seed = 0;
+        hash_combine(seed, v.value());
+        hash_combine(seed, &v.category());
+        return seed;
+    }
+
+    inline std::size_t hash_value(std::error_condition const& v) {
+        std::size_t seed = 0;
+        hash_combine(seed, v.value());
+        hash_combine(seed, &v.category());
+        return seed;
+    }
+#endif
+
     //
     // boost::hash
     //
-    
+
     // Define the specializations required by the standard. The general purpose
     // boost::hash is defined later in extensions.hpp if
     // BOOST_HASH_NO_EXTENSIONS is not defined.
-    
+
     // BOOST_HASH_SPECIALIZE - define a specialization for a type which is
     // passed by copy.
     //

test/Jamfile.v2

@@ -44,6 +44,7 @@ test-suite container_hash/hash
         [ run hash_map_test.cpp ]
         [ run hash_complex_test.cpp ]
         [ run hash_type_index_test.cpp ]
+        [ run hash_system_error_test.cpp ]
         [ run hash_std_array_test.cpp ]
         [ run hash_std_tuple_test.cpp ]
         [ run hash_std_smart_ptr_test.cpp ]

test/hash_info.cpp

@@ -78,4 +78,17 @@ int main() {
     std::cout << "BOOST_HASH_HAS_STRING_VIEW: "
         << BOOST_HASH_HAS_STRING_VIEW
         << std::endl;
+
+#if defined(BOOST_NO_CXX11_HDR_TYPEINDEX)
+    std::cout << "No <typeindex>" << std::endl;
+#else
+    std::cout << "<typeindex>" << std::endl;
+#endif
+
+#if defined(BOOST_NO_CXX11_HDR_SYSTEM_ERROR)
+    std::cout << "No <system_error>" << std::endl;
+#else
+    std::cout << "<system_error>" << std::endl;
+#endif
+
 }

test/hash_system_error_test.cpp

@@ -0,0 +1,55 @@
+
+// Copyright 2018 Daniel James
+// 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)
+
+#include "./config.hpp"
+
+#ifndef BOOST_HASH_TEST_STD_INCLUDES
+#  include <boost/container_hash/hash.hpp>
+#endif
+#include <boost/config.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+#if !defined(BOOST_NO_CXX11_HDR_SYSTEM_ERROR)
+
+#include <system_error>
+
+void test_error_code()
+{
+    std::error_code err1a = std::make_error_code(std::errc::address_family_not_supported);
+    std::error_code err1b = std::make_error_code(std::errc::address_family_not_supported);
+    std::error_code err2 = std::make_error_code(std::errc::address_in_use);
+
+    boost::hash<std::error_code> hasher;
+
+    BOOST_TEST(hasher(err1a) == hasher(err1a));
+    BOOST_TEST(hasher(err1a) == hasher(err1b));
+    BOOST_TEST(hasher(err1a) != hasher(err2));
+}
+
+void test_error_condition()
+{
+    std::error_condition err1a = std::make_error_condition(std::errc::address_family_not_supported);
+    std::error_condition err1b = std::make_error_condition(std::errc::address_family_not_supported);
+    std::error_condition err2 = std::make_error_condition(std::errc::address_in_use);
+
+    boost::hash<std::error_condition> hasher;
+
+    BOOST_TEST(hasher(err1a) == hasher(err1a));
+    BOOST_TEST(hasher(err1a) == hasher(err1b));
+    BOOST_TEST(hasher(err1a) != hasher(err2));
+}
+
+#endif
+
+int main()
+{
+#if !defined(BOOST_NO_CXX11_HDR_SYSTEM_ERROR)
+    test_error_code();
+    test_error_condition();
+#else
+    BOOST_LIGHTWEIGHT_TEST_OSTREAM << "<system_error> not available." << std::endl;
+#endif
+    return boost::report_errors();
+}