From 83a874ed49f55336a95d8e264d36eee431cd949a Mon Sep 17 00:00:00 2001
From: Daniel James <daniel@calamity.org.uk>
Date: Fri, 13 Apr 2018 09:31:18 +0100
Subject: [PATCH] More general purpose support for iterators with odd reference
 type (trac #13501)

In the last release I added explicit support for `vector<bool>` which wasn't
working with libc++ because the iterator's `operator*` returned a proxy
reference type. Other implementations return a `bool` for const iterators, so
they happened to work okay.

This solves the problem in a more general purpose way by instantiating
`hash_combine` for the iterator `value_type`. So the type returned by
`operator*` will be implicitly casted to the correct type.
---
 include/boost/container_hash/extensions.hpp | 51 ---------------------
 include/boost/container_hash/hash.hpp       |  5 +-
 2 files changed, 3 insertions(+), 53 deletions(-)

diff --git a/include/boost/container_hash/extensions.hpp b/include/boost/container_hash/extensions.hpp
index 4eebb4b..393b702 100644
--- a/include/boost/container_hash/extensions.hpp
+++ b/include/boost/container_hash/extensions.hpp
@@ -22,7 +22,6 @@
 #include <boost/detail/container_fwd.hpp>
 #include <boost/core/enable_if.hpp>
 #include <boost/static_assert.hpp>
-#include <vector>
 
 #if !defined(BOOST_NO_CXX11_HDR_ARRAY)
 #   include <array>
@@ -71,56 +70,6 @@ namespace boost
         return seed;
     }
 
-    inline std::size_t hash_range(
-        std::vector<bool>::iterator first,
-        std::vector<bool>::iterator last)
-    {
-        std::size_t seed = 0;
-
-        for(; first != last; ++first)
-        {
-            hash_combine<bool>(seed, *first);
-        }
-
-        return seed;
-    }
-
-    inline std::size_t hash_range(
-        std::vector<bool>::const_iterator first,
-        std::vector<bool>::const_iterator last)
-    {
-        std::size_t seed = 0;
-
-        for(; first != last; ++first)
-        {
-            hash_combine<bool>(seed, *first);
-        }
-
-        return seed;
-    }
-
-    inline void hash_range(
-        std::size_t& seed,
-        std::vector<bool>::iterator first,
-        std::vector<bool>::iterator last)
-    {
-        for(; first != last; ++first)
-        {
-            hash_combine<bool>(seed, *first);
-        }
-    }
-
-    inline void hash_range(
-        std::size_t& seed,
-        std::vector<bool>::const_iterator first,
-        std::vector<bool>::const_iterator last)
-    {
-        for(; first != last; ++first)
-        {
-            hash_combine<bool>(seed, *first);
-        }
-    }
-
     template <class T, class A>
     std::size_t hash_value(std::vector<T, A> const& v)
     {
diff --git a/include/boost/container_hash/hash.hpp b/include/boost/container_hash/hash.hpp
index 76de793..fd814a2 100644
--- a/include/boost/container_hash/hash.hpp
+++ b/include/boost/container_hash/hash.hpp
@@ -18,6 +18,7 @@
 
 #include <boost/container_hash/hash_fwd.hpp>
 #include <functional>
+#include <iterator>
 #include <boost/container_hash/detail/hash_float.hpp>
 #include <string>
 #include <boost/limits.hpp>
@@ -426,7 +427,7 @@ namespace boost
 
         for(; first != last; ++first)
         {
-            hash_combine(seed, *first);
+            hash_combine<typename std::iterator_traits<It>::value_type>(seed, *first);
         }
 
         return seed;
@@ -437,7 +438,7 @@ namespace boost
     {
         for(; first != last; ++first)
         {
-            hash_combine(seed, *first);
+            hash_combine<typename std::iterator_traits<It>::value_type>(seed, *first);
         }
     }