From fe3eac52bfb050e3751edb045e6dd4fa52645bd8 Mon Sep 17 00:00:00 2001
From: jzmaddock <john@johnmaddock.co.uk>
Date: Fri, 2 Dec 2016 17:57:35 +0000
Subject: [PATCH] Fix bit exporting of trivial cpp_ints. Fixes:
 https://svn.boost.org/trac/boost/ticket/12627.

---
 include/boost/multiprecision/cpp_int/import_export.hpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/boost/multiprecision/cpp_int/import_export.hpp b/include/boost/multiprecision/cpp_int/import_export.hpp
index 3ba3442d..7bd843fb 100644
--- a/include/boost/multiprecision/cpp_int/import_export.hpp
+++ b/include/boost/multiprecision/cpp_int/import_export.hpp
@@ -199,8 +199,8 @@ namespace boost {
          template <class Backend>
          inline boost::uintmax_t extract_bits(const Backend& val, unsigned location, unsigned count, const mpl::true_&)
          {
-            boost::uintmax_t result = *val.limbs();
-            boost::uintmax_t mask = count == std::numeric_limits<boost::uintmax_t>::digits ? ~static_cast<boost::uintmax_t>(0) : (static_cast<boost::uintmax_t>(1u) << count) - 1;
+            typename Backend::local_limb_type result = *val.limbs();
+            typename Backend::local_limb_type mask = count >= std::numeric_limits<typename Backend::local_limb_type>::digits ? ~static_cast<typename Backend::local_limb_type>(0) : (static_cast<typename Backend::local_limb_type>(1u) << count) - 1;
             return (result >> location) & mask;
          }