From a9697b88fd3b946d6e8a4a7f678d5b0f7533843d Mon Sep 17 00:00:00 2001
From: Antony Polukhin <antoshkka@gmail.com>
Date: Thu, 8 Dec 2011 15:29:44 +0000
Subject: [PATCH] Fixes #6186 (lexical_cast compliation error fixed, when
 wchar_t is a typedef for unsigned short. Test added)

[SVN r75864]
---
 include/boost/lexical_cast.hpp             | 15 ++++++-
 test/Jamfile.v2                            |  7 ++-
 test/lexical_cast_typedefed_wchar_test.cpp | 50 ++++++++++++++++++++++
 3 files changed, 69 insertions(+), 3 deletions(-)
 create mode 100755 test/lexical_cast_typedefed_wchar_test.cpp

diff --git a/include/boost/lexical_cast.hpp b/include/boost/lexical_cast.hpp
index e7ab248..480d87a 100644
--- a/include/boost/lexical_cast.hpp
+++ b/include/boost/lexical_cast.hpp
@@ -1093,6 +1093,8 @@ namespace boost
 
     namespace detail // optimized stream wrapper
     {
+        struct type_used_as_workaround_for_typedefed_wchar_ts{};
+
         // String representation of Source has an upper limit.
         template< class CharT // a result of widest_char transformation
                 , class Traits // usually char_traits<CharT>
@@ -1354,6 +1356,8 @@ namespace boost
 
 /************************************ HELPER FUNCTIONS FOR OPERATORS >> ( ... ) ********************************/
         private:
+            bool shr_unsigned(type_used_as_workaround_for_typedefed_wchar_ts /*var*/) {return true;}
+
             template <typename Type>
             bool shr_unsigned(Type& output)
             {
@@ -1480,8 +1484,15 @@ namespace boost
             }
 
 /************************************ OPERATORS >> ( ... ) ********************************/
-        public:
-            bool operator>>(unsigned short& output)             { return shr_unsigned(output); }
+
+            typedef BOOST_DEDUCED_TYPENAME ::boost::mpl::if_c<
+                ::boost::is_same<CharT, unsigned short>::value
+                , type_used_as_workaround_for_typedefed_wchar_ts
+                , unsigned short
+            >::type ushort_ambiguity_workaround;
+
+            public:
+            bool operator>>(ushort_ambiguity_workaround& output){ return shr_unsigned(output); }
             bool operator>>(unsigned int& output)               { return shr_unsigned(output); }
             bool operator>>(unsigned long int& output)          { return shr_unsigned(output); }
             bool operator>>(short& output)                      { return shr_signed(output); }
diff --git a/test/Jamfile.v2 b/test/Jamfile.v2
index 6eebe72..e7408f3 100644
--- a/test/Jamfile.v2
+++ b/test/Jamfile.v2
@@ -14,7 +14,12 @@
 
 # bring in rules for testing
 import testing ;
+import feature ;
 
+feature.feature nowchar : on :
+ composite optional propagated link-incompatible ;
+feature.compose <nowchar>on : <cxxflags>/Zc:wchar_t- ; 
+ 
 test-suite conversion
   : [ run implicit_cast.cpp ]
     [ compile-fail implicit_cast_fail.cpp ]
@@ -30,6 +35,6 @@ test-suite conversion
     [ run lexical_cast_inf_nan_test.cpp ../../test/build//boost_unit_test_framework/<link>static ]
     [ run lexical_cast_containers_test.cpp ../../test/build//boost_unit_test_framework/<link>static ]
     [ run lexical_cast_empty_input_test.cpp ../../test/build//boost_unit_test_framework/<link>static ]
+    [ run lexical_cast_typedefed_wchar_test.cpp ../../test/build//boost_unit_test_framework/<link>static : : : <toolset>msvc:<nowchar>on : : ]
   ;
-
       
diff --git a/test/lexical_cast_typedefed_wchar_test.cpp b/test/lexical_cast_typedefed_wchar_test.cpp
new file mode 100755
index 0000000..ae84678
--- /dev/null
+++ b/test/lexical_cast_typedefed_wchar_test.cpp
@@ -0,0 +1,50 @@
+//  Unit test for boost::lexical_cast.
+//
+//  See http://www.boost.org for most recent version, including documentation.
+//
+//  Copyright Antony Polukhin, 2011.
+//
+//  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 <boost/config.hpp>
+
+#if defined(__INTEL_COMPILER)
+#pragma warning(disable: 193 383 488 981 1418 1419)
+#elif defined(BOOST_MSVC)
+#pragma warning(disable: 4097 4100 4121 4127 4146 4244 4245 4511 4512 4701 4800)
+#endif
+
+#include <boost/lexical_cast.hpp>
+#include <boost/test/unit_test.hpp>
+
+void test_typedefed_wchar_t();
+
+using namespace boost;
+
+unit_test::test_suite *init_unit_test_suite(int, char *[])
+{
+    unit_test::test_suite *suite =
+        BOOST_TEST_SUITE("lexical_cast unit test for typedefed wchar_t (mainly for MSVC)");
+    suite->add(BOOST_TEST_CASE(&test_typedefed_wchar_t));
+
+    return suite;
+}
+
+
+void test_typedefed_wchar_t()
+{
+#ifdef BOOST_MSVC
+    BOOST_CHECK((boost::is_same<wchar_t, unsigned short>::value));
+#endif
+
+    BOOST_CHECK_EQUAL(lexical_cast<int>(L"1000"), 1000);
+}
+
+
+
+
+
+
+